It has been years since I have seen a copy of 8.5. The scanner may have marked the plug-ins bad when initially scanned.
Is there an option to re-scan failed plug-ins? It may be in the dialog where the scan path is set. If so.
enable the option,
run a scan,
turn the option off.
The brute force method is
move the plug-in folder out of the scan path,
scan plug-ins,
move the folder back into the scan path,
scan again.