How did you save as IDML?
Did you choose the file type or did you only change the extension to IDML?
Thanks for the response. I created the layout in InDesign 6 and exported the file to idml, so the extension naming was automatic. I tried opening the file from two different workstations in CS6 and on an old Mac laptop in CS4, but no luck. I have exported hdml in the past with no problems.
No luck? Did you get any message?
"Adobe may not support this format, a plug in might be missing." is normally opening if you try to open an INDD in a previous version. That's why I supposed that it might be an INDD file with the wrong extension.
If the file is not corrupted you should be able to open any IDML in CS6 but also in CS4.
If you have saved it with the wrong extension, you could try to replace the wrong extension with a correct one.
You write also HDML? Are you sure that it is also not a HTML file?
Thanks again. Sorry, HDML was a typo--I exported it as an "IDML file, and that was the extension supplied when exported. I did not manually type the extension. I did receive the message mentioned previously when opening in versions 6 or 4.
What do you see, when you select this file in Adobe Bridge? Any hints? Some information? What is the file size?
Otherwise It will be possible that the file has been corrupted.
Good point. I just realized that I didn't check the file size, and it is only 4kb!--so it is definately corrupted. It should be at least 600 Mb. Back to square one. Thanks for your help.