Plug-in not present in the plug-ins folder

[nikydvt]

Suddenly Max 7 Cycling74, nevertheless present between the available inserts, cannot more been utilized in ProTool11 on Windows 8.1 because when I try tu activate it, appears as plug-in inactive and this alert appears:
"the plug-in could not be made active because the plug-in is not present in the plug-ins folder". What could I make? Thanks niky
I also saw, at the opening of the session, this other alert: "the following plug-ins were made inactive because of insufficient system resources" nevertheless untill little time ago it was fuctioning regularly under the same conditions.
I also tried then, in an over-simplified manner to put in the Avid/Audio/Plug-ins folder a link of Max, but without any result.