In CS6 I down saved an InDesign file created in CS5, to CS4. For some reason I did not have the option to down save to CS5 from CS6. Now I cannot open the file in CS6 or CS5. I get an error message that says "Cannot open the file. Adobe ID may not support the file format, a plug in that supports teh file format may be missing, or the file may be open in another application. I know that the CS6 files are .indd and that CS4 and lower are .indl, is there a way for me to revert back to .indd?
I'm not following any of this. CS6 can export or save to IDML which can
be opened in CS4 or later.
The file that I opened and worked in was originally created in cs5. I have cs6 now, and when I saved the file I wanted to save it to cs 5--so that my co workers who have cs5 can still work in the file. When I selected "save as" I was only give the option to save down to cs4 or lower, so that is what I did. Now I have this .idml file that I am unable to open. Exporting the file doesn't seem to be an option since I originally "saved as" instead of exporting the file.
Read it again. That's not CS4 or lower, it's CS4 or higher.
Save as and exporting to IDML produce identical results.
I think you may simply be dealing with a corrupt file.