Error badge in IDE

PlatformIO IDE
1

Suddenly I got this badge in IDE:

Everything compiles cleanly, yet still IDE shows me this and an error message “Arduino.h: No such file or directory at line 1 col 21”. Restarting IDE does not change anything, the badge and message reappears upon 1st project save.

2

Do you have the same issue on other projects?

3

Yes but it’s false alarm, hit “Rebuild project index” and it’s gone.