diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index be44d9b34b68ed01f746a95edd8f19488480c05b..1854a42a694896a413572c324941a92d6757963c 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -89,7 +89,7 @@ test:
     - mkdir build
     - cd build
     - VERSION="$(conan inspect --raw version ..)"
-    - conan install -s "compiler.libcxx=libstdc++11" -o build_acm=True .. "caosdb/$VERSION@_/_"
+    - conan install -s "compiler.libcxx=libstdc++11" --build=missing -o build_acm=True .. "caosdb/$VERSION@_/_"
     - cmake -DCMAKE_BUILD_TYPE=Debug ..
     - cmake --build . -j
     - cmake --build . -j --target unit_test_coverage
diff --git a/CMakeLists.txt b/CMakeLists.txt
index fa8e56fc1737c9b1eb3b20cce26bb0a08e976fbd..cf4774183f458f27b89fdc5e1f6d79ad53383134 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -20,7 +20,7 @@
 
 cmake_minimum_required(VERSION 3.13)
 
-set(libcaosdb_VERSION 0.2.0)
+set(libcaosdb_VERSION 0.2.1)
 set(libcaosdb_COMPATIBLE_SERVER_VERSION_MAJOR 0)
 set(libcaosdb_COMPATIBLE_SERVER_VERSION_MINOR 8)
 set(libcaosdb_COMPATIBLE_SERVER_VERSION_PATCH 0)
diff --git a/Makefile b/Makefile
index 21cd43348cb545bfbf0acd8985dd0e3a459ca8f1..4be361a56cb09fa5359d5ef03ccff3064b2e4e3d 100644
--- a/Makefile
+++ b/Makefile
@@ -79,7 +79,7 @@ conan: conan-install conan-create
 .PHONY: conan
 
 doc:
-	mkdir -p build && cd build && conan install .. -s $(CONAN_SETTINGS) \
+	mkdir -p build && cd build && conan install .. --build=missing -s $(CONAN_SETTINGS) \
 	  && cmake .. && cmake --build . --target doc-sphinx \
 	  && echo "The documentation starts at build/doc/sphinx_out/index.html ."
 .PHONY: doc
diff --git a/RELEASE_GUIDELINES.md b/RELEASE_GUIDELINES.md
index c725ec86fd0fb5f8019da955bbe5999ff47afe25..faa7d4399c10ea4e0b45c48943d122ac15fbef5b 100644
--- a/RELEASE_GUIDELINES.md
+++ b/RELEASE_GUIDELINES.md
@@ -41,4 +41,8 @@ guidelines of the CaosDB Project
 9. Release cppinttests with updated cpplib version
 
 10. Merge `main` back into `dev` and increase patch version by one to begin next
-    release cycle. Do the same in cppintest.
+    release cycle.
+    * update `conanfile.py`
+    * update `CMakeLists.txt`
+    * update `CHANGELOG.md` with empty `[Unreleased]` sections.
+    * Don't forget to update cppintest.
diff --git a/conanfile.py b/conanfile.py
index 156bd99fee0a9fb695487edc1ffc8c785f5717b2..fbcb39a730089ae8a113a5d411fefd8788ba08a2 100644
--- a/conanfile.py
+++ b/conanfile.py
@@ -3,7 +3,7 @@ from conans import ConanFile, CMake, tools
 
 class CaosdbConan(ConanFile):
     name = "caosdb"
-    version = "0.2.0"
+    version = "0.2.1"
     license = "AGPL-3.0-or-later"
     author = "Timm C. Fitschen <t.fitschen@indiscale.com>"
     url = "https://gitlab.indiscale.com/caosdb/src/caosdb-cpplib.git"
@@ -22,10 +22,10 @@ class CaosdbConan(ConanFile):
     }
     generators = "cmake"
     requires = [
-        ("grpc/1.45.2"),
+        ("grpc/1.48.0"),
     ]
     build_requires = [
-        ("boost/1.77.0"),
+        ("boost/1.78.0"),
         ("gtest/1.11.0"),
     ]
     exports = ("*.cmake", "*CMakeLists.txt", "*.in",
@@ -38,6 +38,7 @@ class CaosdbConan(ConanFile):
         if self.settings.os == "Windows":
             del self.options.fPIC
         self.options["boost"].without_python = True
+        self.options["boost"].filesystem_version = "3"
 
     # def source(self):
         # self.run("git clone https://gitlab.indiscale.com/caosdb/src/caosdb-cpplib.git")
diff --git a/doc/CHANGELOG.md b/doc/CHANGELOG.md
index e3af12debeb7ca2a6e3a6d69b7c88e886978fa4f..8f8b536d5f9810c4a565cd07866dfe56388ad979 100644
--- a/doc/CHANGELOG.md
+++ b/doc/CHANGELOG.md
@@ -5,6 +5,14 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [0.2.1] - 2022-09-22 ##
+(Daniel Hornung)
+
+### Changed ###
+
+* Updated dependencies
+* Simplified implementation code a bit
+
 ## [0.2.0] - 2022-07-13
 (Timm Fitschen)
 
@@ -19,19 +27,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 * Transaction::ExecuteAsynchronously is actually asynchronous now.
 * Removed boost from the headers. Boost is only a build dependency from now on.
 
-### Deprecated
-
-### Removed
-
 ### Fixed
 
 * Calling "GetFileDescriptor().wrapped->path()" after retrieval leads to SegFault.
 - #41 Updated Conan version in CI pipeline.
 
-### Security
-
-### Documentation
-
 ## [0.1.2] - 2022-05-31
 (Florian Spreckelsen)
 
diff --git a/include/caosdb/logging.h b/include/caosdb/logging.h
index 94c78ed3d6c303149e755c4aa83e757a04500724..3fda8e83ac5c164728b2cd156292d22952b70130 100644
--- a/include/caosdb/logging.h
+++ b/include/caosdb/logging.h
@@ -2,8 +2,8 @@
 /*
  * This file is a part of the CaosDB Project.
  *
- * Copyright (C) 2021 Timm Fitschen <t.fitschen@indiscale.com>
- * Copyright (C) 2021 IndiScale GmbH <info@indiscale.com>
+ * Copyright (C) 2021-2022 Timm Fitschen <t.fitschen@indiscale.com>
+ * Copyright (C) 2021-2022 IndiScale GmbH <info@indiscale.com>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
@@ -27,7 +27,6 @@
 #include <cstdint>            // for uint64_t
 #include <iosfwd>             // for streamsize
 #include <memory>             // for shared_ptr
-#include <ostream>            // for ostream
 #include <string>             // for string
 #include <vector>             // for vector
 
diff --git a/requirements.txt b/requirements.txt
index 171a4c323631116bbd3cfc3019035d77cc1cad6e..2ef354530924d65208089d8825e3a9876f638775 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,29 +1,22 @@
-attrs==21.2.0
-bottle==0.12.19
-certifi==2021.10.8
-chardet==4.0.0
-charset-normalizer==2.0.7
-colorama==0.4.4
-conan==1.48.0
-deprecation==2.1.0
+bottle==0.12.21
+certifi==2022.6.15
+charset-normalizer==2.1.0
+colorama==0.4.5
+conan==1.52.0
 distro==1.6.0
-fasteners==0.16.3
+fasteners==0.17.3
 future==0.18.2
-idna==3.2
-Jinja2==3.1.1
-jsonschema==4.1.0
-MarkupSafe==2.0.1
+idna==3.3
+Jinja2==3.1.2
+MarkupSafe==2.1.1
 node-semver==0.6.1
-packaging==21.0
 patch-ng==1.17.4
 pluginbase==1.0.1
-Pygments==2.10.0
-PyJWT==1.7.1
-pyparsing==2.4.7
-pyrsistent==0.18.0
+Pygments==2.12.0
+PyJWT==2.4.0
 python-dateutil==2.8.2
 PyYAML==5.4.1
-requests==2.26.0
+requests==2.28.1
 six==1.16.0
-tqdm==4.62.3
-urllib3==1.26.7
+tqdm==4.64.0
+urllib3==1.26.9
diff --git a/src/caosdb/connection.cpp b/src/caosdb/connection.cpp
index abc87dacb054a570540eff7e896eb1058b7b267b..4c77c5254c1300e908622882cd01d29d7b0aab65 100644
--- a/src/caosdb/connection.cpp
+++ b/src/caosdb/connection.cpp
@@ -2,8 +2,8 @@
  *
  * This file is a part of the CaosDB Project.
  *
- * Copyright (C) 2021 Timm Fitschen <t.fitschen@indiscale.com>
- * Copyright (C) 2021 IndiScale GmbH <info@indiscale.com>
+ * Copyright (C) 2021-2022 Timm Fitschen <t.fitschen@indiscale.com>
+ * Copyright (C) 2021-2022 IndiScale GmbH <info@indiscale.com>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
@@ -25,18 +25,17 @@
 #include "caosdb/acm/v1alpha1/main.grpc.pb.h" // for AccessControlMan...
 #include "caosdb/acm/v1alpha1/main.pb.h"      // for CreateSingleUser...
 #endif
-#include "caosdb/configuration.h"            // for ConnectionConfigur...
-#include "caosdb/exceptions.h"               // for ConfigurationError
-#include "caosdb/info.h"                     // for VersionInfo
-#include "caosdb/info/v1/main.grpc.pb.h"     // for GeneralInfoService
-#include "caosdb/info/v1/main.pb.h"          // for GetVersionInfoRequest
-#include "caosdb/transaction.h"              // for Transaction
-#include "caosdb/transaction_status.h"       // for TransactionStatus
-#include <grpcpp/client_context.h>           // for ClientContext
-#include <grpcpp/create_channel.h>           // for CreateChannel
-#include <grpcpp/support/status.h>           // for Status
-#include <grpcpp/support/status_code_enum.h> // for StatusCode, UNAUTHENTIC...
-#include <string>                            // for string, operator+
+#include "caosdb/configuration.h"        // for ConnectionConfigur...
+#include "caosdb/exceptions.h"           // for ConfigurationError
+#include "caosdb/info.h"                 // for VersionInfo
+#include "caosdb/info/v1/main.grpc.pb.h" // for GeneralInfoService
+#include "caosdb/info/v1/main.pb.h"      // for GetVersionInfoRequest
+#include "caosdb/transaction.h"          // for Transaction
+#include "caosdb/transaction_status.h"   // for TransactionStatus
+#include <grpcpp/client_context.h>       // for ClientContext
+#include <grpcpp/create_channel.h>       // for CreateChannel
+#include <grpcpp/support/status.h>       // for Status
+#include <string>                        // for string, operator+
 // IWYU pragma: no_include "net/proto2/public/repeated_field.h"
 
 namespace caosdb::connection {
diff --git a/src/caosdb/file_transmission/download_request_handler.cpp b/src/caosdb/file_transmission/download_request_handler.cpp
index 821ed79477045f4e3bf49c061cfac622b814700d..1b0764fa2039b7d4c37ba09fdc03cedf4959736a 100644
--- a/src/caosdb/file_transmission/download_request_handler.cpp
+++ b/src/caosdb/file_transmission/download_request_handler.cpp
@@ -1,7 +1,7 @@
 /*
  * This file is a part of the CaosDB Project.
- * Copyright (C) 2021 Timm Fitschen <t.fitschen@indiscale.com>
- * Copyright (C) 2021 IndiScale GmbH <info@indiscale.com>
+ * Copyright (C) 2021-2022 Timm Fitschen <t.fitschen@indiscale.com>
+ * Copyright (C) 2021-2022 IndiScale GmbH <info@indiscale.com>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
@@ -47,21 +47,20 @@
  * > DEALINGS IN THE SOFTWARE.
  */
 #include "caosdb/file_transmission/download_request_handler.h"
-#include "caosdb/logging.h"                  // for CAOSDB_LOG_TRACE
-#include "caosdb/protobuf_helper.h"          // for get_arena
-#include "caosdb/status_code.h"              // for GENERIC_RPC_E...
-#include "caosdb/transaction_status.h"       // for TransactionStatus
-#include <exception>                         // IWYU pragma: keep
-#include <filesystem>                        // for operator<<, path
-#include <google/protobuf/arena.h>           // for Arena
-#include <grpcpp/client_context.h>           // for ClientContext
-#include <grpcpp/completion_queue.h>         // for CompletionQueue
-#include <grpcpp/support/async_stream.h>     // for ClientAsyncReader
-#include <grpcpp/support/status.h>           // for Status
-#include <grpcpp/support/status_code_enum.h> // for OK
-#include <stdexcept>                         // for runtime_error
-#include <string>                            // for string, opera...
-#include <utility>                           // for move
+#include "caosdb/logging.h"              // for CAOSDB_LOG_TRACE
+#include "caosdb/protobuf_helper.h"      // for get_arena
+#include "caosdb/status_code.h"          // for GENERIC_RPC_E...
+#include "caosdb/transaction_status.h"   // for TransactionStatus
+#include <exception>                     // IWYU pragma: keep
+#include <filesystem>                    // for operator<<, path
+#include <google/protobuf/arena.h>       // for Arena
+#include <grpcpp/client_context.h>       // for ClientContext
+#include <grpcpp/completion_queue.h>     // for CompletionQueue
+#include <grpcpp/support/async_stream.h> // for ClientAsyncReader
+#include <grpcpp/support/status.h>       // for Status
+#include <stdexcept>                     // for runtime_error
+#include <string>                        // for string, opera...
+#include <utility>                       // for move
 // IWYU pragma: no_include <bits/exception.h>
 //
 namespace caosdb::transaction {
diff --git a/src/caosdb/file_transmission/upload_request_handler.cpp b/src/caosdb/file_transmission/upload_request_handler.cpp
index 32bb8132e0b4a966774c5f8111800151895b6ced..57bd224dfe53a57ecb706d74dc1438e143dac641 100644
--- a/src/caosdb/file_transmission/upload_request_handler.cpp
+++ b/src/caosdb/file_transmission/upload_request_handler.cpp
@@ -1,7 +1,7 @@
 /*
  * This file is a part of the CaosDB Project.
- * Copyright (C) 2021 Timm Fitschen <t.fitschen@indiscale.com>
- * Copyright (C) 2021 IndiScale GmbH <info@indiscale.com>
+ * Copyright (C) 2021-2022 Timm Fitschen <t.fitschen@indiscale.com>
+ * Copyright (C) 2021-2022 IndiScale GmbH <info@indiscale.com>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
@@ -57,7 +57,6 @@
 #include <filesystem>                        // for operator<<, path
 #include <google/protobuf/arena.h>           // for Arena
 #include <grpcpp/impl/codegen/call_op_set.h> // for WriteOptions
-#include <grpcpp/support/status_code_enum.h> // for OK
 #include <string>                            // for basic_string
 #include <utility>                           // for move
 // IWYU pragma: no_include <bits/exception.h>
diff --git a/src/caosdb/transaction.cpp b/src/caosdb/transaction.cpp
index c75fdeb7fcf5b1a5854464dcabf76c11bb5a4262..ca8338dce4e4b721202e72c3fdecf58339746ee0 100644
--- a/src/caosdb/transaction.cpp
+++ b/src/caosdb/transaction.cpp
@@ -1,7 +1,7 @@
 /*
  * This file is a part of the CaosDB Project.
- * Copyright (C) 2021 Timm Fitschen <t.fitschen@indiscale.com>
- * Copyright (C) 2021 IndiScale GmbH <info@indiscale.com>
+ * Copyright (C) 2021-2022 Timm Fitschen <t.fitschen@indiscale.com>
+ * Copyright (C) 2021-2022 IndiScale GmbH <info@indiscale.com>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
@@ -32,7 +32,7 @@
 #include <filesystem>                                              // for operator<<, path
 #include <future>                                                  // for async, future
 #include <google/protobuf/arena.h>                                 // for Arena
-#include <grpc/impl/codegen/gpr_types.h>                           // for gpr_timespec
+#include <grpc/grpc.h>                                             // for gpr_timespec
 #include <map>                                                     // for map, operator!=
 #include <memory>                                                  // for unique_ptr
 #include <random>                                                  // for mt19937, rand...
diff --git a/src/caosdb/unary_rpc_handler.cpp b/src/caosdb/unary_rpc_handler.cpp
index 06afc127cecea22b1b805d20a68eab177841e981..6d116eafae7203498ebf431a09d85c184b619191 100644
--- a/src/caosdb/unary_rpc_handler.cpp
+++ b/src/caosdb/unary_rpc_handler.cpp
@@ -1,7 +1,7 @@
 /*
  * This file is a part of the CaosDB Project.
- * Copyright (C) 2021 Timm Fitschen <t.fitschen@indiscale.com>
- * Copyright (C) 2021 IndiScale GmbH <info@indiscale.com>
+ * Copyright (C) 2021-2022 Timm Fitschen <t.fitschen@indiscale.com>
+ * Copyright (C) 2021-2022 IndiScale GmbH <info@indiscale.com>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
@@ -47,11 +47,10 @@
  * > DEALINGS IN THE SOFTWARE.
  */
 #include "caosdb/unary_rpc_handler.h"
-#include "caosdb/logging.h"                  // for CAOSDB_LOG_TRACE
-#include "caosdb/status_code.h"              // for GENERIC_RPC_E...
-#include <exception>                         // IWYU pragma: keep
-#include <grpcpp/support/status_code_enum.h> // for OK
-#include <string>                            // for string, opera...
+#include "caosdb/logging.h"     // for CAOSDB_LOG_TRACE
+#include "caosdb/status_code.h" // for GENERIC_RPC_E...
+#include <exception>            // IWYU pragma: keep
+#include <string>               // for string, opera...
 // IWYU pragma: no_include <bits/exception.h>
 
 namespace caosdb::transaction {
diff --git a/test/test_transaction.cpp b/test/test_transaction.cpp
index e710b6c775615968b567b6efa64ba76e56717c69..77d457c6eee2c5e9d95c53c95c1b2f0a713dcff4 100644
--- a/test/test_transaction.cpp
+++ b/test/test_transaction.cpp
@@ -1,8 +1,8 @@
 /*
  * This file is a part of the CaosDB Project.
  *
- * Copyright (C) 2021 Timm Fitschen <t.fitschen@indiscale.com>
- * Copyright (C) 2021 IndiScale GmbH <info@indiscale.com>
+ * Copyright (C) 2021-2022 Timm Fitschen <t.fitschen@indiscale.com>
+ * Copyright (C) 2021-2022 IndiScale GmbH <info@indiscale.com>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
@@ -55,10 +55,10 @@ TEST(test_transaction, create_transaction) {
   auto transaction = connection.CreateTransaction();
 
   ASSERT_EQ(StatusCode::GO_ON, transaction->RetrieveById("100"));
-  EXPECT_THROW_MESSAGE(transaction->Execute(), ConnectionError,
-                       "The attempt to execute this transaction was not successful because the "
-                       "connection to the server could not be established. "
-                       "Original message: failed to connect to all addresses");
+  EXPECT_THROW_STARTS_WITH(transaction->Execute(), ConnectionError,
+                           "The attempt to execute this transaction was not successful because the "
+                           "connection to the server could not be established. "
+                           "Original message: failed to connect to all addresses");
 }
 
 TEST(test_transaction, test_multi_result_set) {