Cannot open my ID file!

[defaultmfuj86iv2kb1]

The InDesign file I have been working all day is now unable to open. The message reads...

"Cannot open. 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 have been saving down my files to have access on my MacBook Pro which does not suppoer the latest version of ID. I have tried everything I can think of. Any ideas?

[Bill Silbert]

When you say that you've been"saving down" your files do you mean that you've been exporting them as IDMLs? Have you been going back and forth with your files over and over switching between the two computers that you are using? Using IDMLs in this fashion (back and forth numerous times) is not a good idea. I have seen some funky things happen to InDesign files that have done the "back and forth" although not to this extreme. An IDML used sparingly can actually remove corruption from an InDesign file but it can be an instrument of corruption as well. 

Is this problem happening with just one document or all of your files? What are the two versions of InDesign that your two machines are running? Have you tried opening the file on another computer?

There are a number of file recovery services on the internet but I cannot personally recommend one. If you can't get this file fixed then hopefully, you have an earlier version of the file in question backed up someplace. Being meticulous about backing up files can certainly save a lot of grief.

[Eugene Tyson]

https://helpx.adobe.com/indesign/kb/troubleshoot-file-issues.html

There's also an email address at the end. 

[Peter Spier]

Is it possible you forgot to "save down" last time?