Ran into a strange bug today when trying to import a solution from a dev environment to another organisation.
I had 2 new entities in the new solution. Entity 1 had a form which included a Quickview form from Entity 2.
When the import solution process (importing to another environment) got to importing Entity 1, it failed with:
|systemform With Id = 210d0997-ebab-4b6b-9e35-6487cfbfe509 Does Not Exist
Upon doing some investigating in the database, I found that the form it was complaining about was the QuickView form from Enitity 2.
I checked the log file of the error and saw Entity 2 was further down the queue of the import process.. so the new QuickView form had not yet been created.
To resolve the issue, I had to remove the QuickView form from Entity 1's form in the Dev solution, then export & import the solution to ORG 2 again, then add the quickview form back on my dev environment and then import again. (I was importing as managed).
Hopefully this bug will be resolved in a future update rollup