unlock a file

You motion array file is likely still a zip file. Extract the contents and then try and open it. 

After Effects will only open if you click on an AEP file or an AET (After Effects Template). Trying to open any other file type by double-clicking on the file is not going to work.

You'll have to import the file, not try and open it unless the extension is .AEP or .AET

it seems it's something related to Motion array extension, try to contact Motion array support to get the correct answer. maybe you subscription is expired and you can't use the template anymore.