Comment 24 for bug 1986976

chronological information : This kind of problems (flashing screen, during boot, logoff or suspend) occured with 18.04 in July 2019 (at install of my new laptop) - With the software update dated around 21Jan2020 on 18.04 the problems were definitely fixed even with 20.04 install on 6oct2020. Problem was viable (avoiding some features) but I never opened an issue !

current problem arose a few days ago after upgrade to 20.04.1 - I seems to me strictly related to my multi-processor installation.
Boot messages are the folowing N double lines about PR01 up to PR07 symbols
ACPI Error Aborting method \_PR.PR01._CPC due to previous AE-NOT-FOUND 20210730
ACPI BIOS Error could not resolved psparser-529 symbols (and other line numbers in seq)