Hello everybody!
I am trying to download the "stm32duino" libruary. At the following way 'File->Preferences->Settings->Additional Boards Manager URLs' I linked
BoardManagerFiles/package_stm_index.json at main · stm32duino/BoardManagerFiles · GitHub. By the next step I opened 'Tools->Board: ->Board manager'. After all I got the next massage from IDE: "Skipping contributed index file C:\Users\Work\AppData\Local\Arduino15\package_stm_index.json, parsing error occured:
com.fasterxml.jackson.core.JsonParseException: Unexpected character ('<' (code 60)): expected a valid value (number, String, array, object, 'true', 'false' or 'null')
at [Source: (FileInputStream); line: 7, column: 2]"
Thanks for watching!
P.S. I tried to reinstall "package_stm_index.json" in Arduino15. Renamed it like "package_stm_index.json.bak".