I recently had to move a form to another package, because we decided to extract some functionality to its own independent package. I moved files, built both packages and everything looked fine, so I started making changes for a new requirement.

But later I noticed something strange in the form. When I opened the form, it didn’t look right. Some new controls (added after the move) were missing and other parts behaved incorrectly (I won’t go into details here). Everything went back to normal when I refreshed the page, but the problem appeared again when I opened the form from menu. Using the refresh button inside the form (beside buttons Open in Microsoft Office and attachments) end up with an error and the application froze.

After making sure that everything is built correctly and restarting everything, I duplicated the form and tried the copy. It worked flawlessly, proving that the form itself was implemented correctly. Therefore, I suspected that the environment somehow used a cached design of the form as it was defined in the old package. Building the packages with and without Build Pre-Compiled Form didn’t make any difference, so I tried one more thing.

I searched the packages directory for the name of my form and I did find something suspicious. There was a file in WebContent subfolder of the original package:

[…]\PackagesLocalDirectory\MyOriginalPackage\WebContent\Forms\myform.json

Just deleting the file didn’t fix the problem, but restarting the server after that did. It would be likely sufficient to restart IIS; I turned the whole machine off because I went home and tried the result the next day.

I wanted to write this down because others might run into the same problem. And it looks like a bug in Microsoft tools, therefore they should look at it and fix it.