Guys, I checked clean installation with exact same configuration as StuBerg but found no issues in CBS.log. Is it possible you have some left-overs there that may be broken?
These folders should be present in WinSxs directory (Vista+ x64):
amd64_avast.vc110.crt_2036b14a11e83e4a_11.0.60610.1_none_d58a6d64ab65b396
amd64_avast.vc140.crt_fcc99ee6193ebbca_14.0.23918.0_none_53c8344321b452ba
x86_avast.vc110.crt_2036b14a11e83e4a_11.0.60610.1_none_1d37a43bbfe1dc9c
x86_avast.vc140.crt_fcc99ee6193ebbca_14.0.23918.0_none_9b756b1a36307bc0
x86_avast.vc140.mfc_fcc99ee6193ebbca_14.0.23918.0_none_a0556d0c3304aaf3
The problem was introduced by earlier Avast software installs and now, it may well be ok to install 12.1.2272 on a clean machine. However, for PCs with the problem, the new version 12.1.2272 does not fix the issue.
Please advise, with step-by-step instructions, how users with the problem, are to supposed to eradicate the problem. It is now 4 weeks that I have struggled with this and still no resolution.
... in addition, here is the [SR] text extracted from the CBS.log after installing Avast Free Edition 12.1.2272, using Stuberg's findstr cmd:
2016-06-25 17:13:03, Info CSI 00004f2d [SR] Cannot verify component files for Avast.VC140.CRT, version 14.0.23918.0, arch amd64, versionScope neutral, pkt {l:8 b:fcc99ee6193ebbca}, type [l:5]"win32", manifest is damaged (TRUE)
2016-06-25 17:13:03, Info CSI 00004f30 [SR] Cannot verify component files for Avast.VC110.CRT, version 11.0.60610.1, arch amd64, versionScope neutral, pkt {l:8 b:2036b14a11e83e4a}, type [l:5]"win32", manifest is damaged (TRUE)
2016-06-25 17:13:03, Info CSI 00004f33 [SR] Cannot verify component files for Avast.VC140.CRT, version 14.0.23918.0, arch x86, versionScope neutral, pkt {l:8 b:fcc99ee6193ebbca}, type [l:5]"win32", manifest is damaged (TRUE)
2016-06-25 17:13:03, Info CSI 00004f36 [SR] Cannot verify component files for Avast.VC140.MFC, version 14.0.23918.0, arch x86, versionScope neutral, pkt {l:8 b:fcc99ee6193ebbca}, type [l:5]"win32", manifest is damaged (TRUE)
2016-06-25 17:13:03, Info CSI 00004f39 [SR] Cannot verify component files for Avast.VC110.CRT, version 11.0.60610.1, arch x86, versionScope neutral, pkt {l:8 b:2036b14a11e83e4a}, type [l:5]"win32", manifest is damaged (TRUE)
2016-06-25 17:13:03, Info CSI 00004f3a [SR] Cannot verify component files for policy.11.0.Avast.VC110.CRT, version 11.0.60610.1, arch x86, versionScope neutral, pkt {l:8 b:2036b14a11e83e4a}, type [l:12]"win32-policy", manifest is damaged (FALSE)
PLEAS NOTE: this log is the same as the log posted by cookiebear66 below, except I have an additional reference to policy.11.0.Avast.VC110.CRT, version 11.0.60610.1, arch x86.