IDMLs A Cautionary Tale
There has been a lot written on this forum about when to use and when not to use InDesign’s IDML export option. It’s original intent was to provide a way to open documents created in a newer version of the program than the one in which a user might be working with the warning that any newer features that the current version has would not translate when opened in the older program. The feature was never intended as a way to be used as a back and forth conduit between versions of InDesign—a fact which has been made clear on this forum repeatedly. As, hopefully, a helpful reinforcement of that warning I wanted to report a situation which may add more weight to the warning against wanton use of the IDML. I recently was in a situation which revealed some additional perils and pitfalls that will result from using IDML files in a manner for which they were never designed.
In the advertising agency in which I work it has always been my job to field test each new version of InDesign, Illustrator and Photoshop before they are rolled out to the rest of the company. Due to a problem with updating the Mac OS globally (the agency was still on Yosemite) the amount of time in which I was the only user of the newer version—which usually is, at most, a couple of weeks—became a couple of months. In this period every InDesign job that I worked on had to have an IDML made so that others in my department would be able to work on them. Things actually didn’t go too badly until after the third or fourth time some jobs had gone back and forth between CC 2017 and CC 2018. The first thing that we started to notice was that when the job was opened in CC 2017 the pasteboard disappeared. When I opened the same IDML file with CC 2018 it was fine. Fortunately, reestablishing the pasteboard in the Guides and Pasteboard section of InDesign preferences using CC 2017 fixed the problem and we never actually lost a file because of it. This was a mixed blessing, however, since it still delayed the urgency of getting everybody updated. What finally drove that decision, though, was after the fifth or sixth time some jobs went back and forth between the versions we started to notice that text was beginning to rerag. That did it. Everybody finally got updated. IDML crisis over.
I should point out, as I’ve seen written here many times, the IDML can be a force for good when there is some minor corruption in an existing file. Exporting the corrupted file as an IDML and then opening it up in the same version can do a world of good. As with all things, there is a time and place for everything.

