InDesign Plug-In Error

[DT1616]

Hello,

I'm having trouble opening my InDesign files all of a sudden. I keep getting an error that says "Adobe InDesign may not support the file format, a plug-in that supports the file format may be missing, or the file may be open in another application." I just had these files open this morning and now I get this error when trying to open any of them. I thought it might have to do with low storage on my Mac, but I delete files and created more storage so I'm not sure what to do. How do I fix this? 

 

[Peter Spier]

First thing to check is if there is a lock file (.idlk) in the folder withthe .indd. They are supposed to be deleted when a file is closed, but sometimes things happen. If you find one, and the file is not in use by someone else, you can delete the .idlk file and your .indd document should open.

[DT1616]

I could not find any .idlk files 

[Peter Spier]

And you have file extensions showing?

[BobLevine]

Is this file in a cloud storage folder such as Dropbox, iCloud or OneDrive?

[DT1616]

-No not in anything like that, the files are all on my desktop 

[Test Screen Name]

Was there a crash or power cut while InDesign was running? 

[Manan Joshi]

Check the filesize and see if it looks too small or too large. A suspicious filesize could point to a corrupted file.

-Manan