DynamicJsonBuffer/StaticJsonBuffer is a class from ArduinoJson 5

If you try to compile a program written for ArduinoJson 5 when version 6 is installed, you get one of the following error:

error: DynamicJsonBuffer is a class from ArduinoJson 5. Please see arduinojson.org/upgrade to learn how to upgrade your program to ArduinoJson version 6
error: StaticJsonBuffer is a class from ArduinoJson 5. Please see arduinojson.org/upgrade to learn how to upgrade your program to ArduinoJson version 6

To fix this error, you must either:

• Downgrade the installed version of ArduinoJson:

  • Open the Arduino Library Manager
  • Search “ArduinoJson”
  • Select version 5.13.5
  • Click “Install”

  (See the picture below.)

• Upgrade your program:

  • Follow the instructions from the migration guide