• "Check for updates" in "Board and Library" manager now uses the latest arduino.cc index urls. The previous versions from arduino.cc no longer work and return invalid json. That caused an issue in Visual Micro. This might show as a board and library load error. Please use this latest release shown below.
  

Visual Micro 22.04.29.3 for VS 2022
Visual Micro 22.04.29.3 for VS 2017/2019

Visual Micro 22.04.29.3 for AS7 (vsInstaller)

If you have the incorrect index files from previous use of the "Check for updates" button in the Board Manager or Library Manager? After updating you should to click the "Check for Updates" button again on BOTH "board manager" and "library manager". After that clicking rescan or restarting the ide will work without issue.