**CMK version: 2.1.0.cre **
OS version: Ubuntu 20.0.4 LTS
Error message: Failed to auto-migrate legacy plugin to section:
After updating chekmk from 2.0.0p23 to the latest at that time 2.1.0 version a “Failed to auto-migrate legacy plugin to section…” error appeared. Also running cmk -R reported all these errors.
Solution was to delete /var/check_mk/precompiled_checks folder and re-run cmk -R. After which everything worked ok.
This suggestion was found in an older thread here.
Best regards,
M