If you are using a recent version of the IDE, you will get an auto-update offer simply by starting the IDE.
Otherwise, the release is available for download here:
https://www.arduino.cc/en/software
This is a minimal bugfix patch release. If you are upgrading from Arduino IDE 2.1.1, please also check the more significant changelog for the 2.2.0 release:
https://forum.arduino.cc/t/arduino-ide-2-2-0-is-now-available/1163477
Thanks so much to the forum community for all the valuable testing and feedback that has helped us greatly in identifying and investigating these bugs and enhancements!
Fix incomplete certificate chain when using Upload SSL Root Certificates with UNO R4 WiFi
arduino/arduino-fwuploader#216, arduino/arduino-ide#2206
Support for using the IDE's "Firmware Updater" feature with the UNO R4 WiFi board was added in the Arduino IDE 2.2.0 release.
That change also caused the UNO R4 WiFi board to be recognized by the "Upload SSL Root Certificates" feature. However, a bug in that tool caused the chains produced by uploading certificates to that board to be incomplete, causing attempts to connect the board to servers via SSL to fail. This bug has been fixed and the IDE's Upload SSL Root Certificates feature now provides a convenient way to upload certificates to the Wi-Fi module of the UNO R4 WiFi board.
Fix missing translations for certain languages
arduino/arduino-ide#2202, arduino/arduino-ide#2201
A regression caused the translations of the Arduino-specific strings in the IDE's UI to be lost for the русский and Türkçe languages. The missing translations have now been resored.
The community work to make Arduino IDE accessible to everyone in the world through localization of the text of the IDE's UI continues, reaching high coverage levels for 18 languages!
If you would like to contribute to the Arduino IDE translations, please see the information here:
(Thanks @metehoca)
Full changelog here:
https://github.com/arduino/arduino-ide/releases/tag/2.2.1
If you have any questions or feedback please post here in the dedicated forum category for Arduino IDE 2.x:
https://forum.arduino.cc/c/software/ide-2-x/93
If you want to see the list of known issues, work in progress, submit a formal report, or contribute to development, the Arduino IDE 2.x source code is hosted in this public repository: