Could not read the file because the plug in could not understand the file

[Jon Reynolds_RCPL]

All of a sudden i am not being able to open my ai files.  Error message of "Could not read the file because the plug in could not understand the file".

Read a couple of threads and the solutions seam to be for mac OS users.  I am on windows 10.

I have no special plug-ins installed. 

Tried moving the files from the cloud sever to hard disk

Any urgent help will be greatly appreciated

[Monika Gause]

AI files?

Did you already reboot the computer?