Can't call method "Id" on an undefined value

RT Users
1

Hi,
I’ve upgraded rt3.8.7 to 3.8.8 and I have this error message "Can’t call
method “Id” on an undefined value at
/usr/local/share/request-tracker3.8/plugins/RT-FM/lib/RT/URI/fsck_com_rtfm.pm
line 133."
when I click to one solved ticket.
I have RTFM2.4.2