We had to merge two applications, so I created a background agent which copied all required documents to the “new” database. The customer tested and we set a due date for the real migration.
The night before actual migration I run an agent which deleted all “test” migration documents before the real agent to copy the documents run again!
Next morning I came to the office and thought: oh my dear. something went wrong! Only a few dozen documents had been copied, I thought!
So I rerun the agent again. First all seemed to be fine. Then a few hours later documents started disappearing. With no obvious reasons.
It took me about 3 hours to figure out that the method document.copyToDatabase would create the same UniversalId again!
So after having deleted the first round of “test” documents and recopied again at due date, the universalids of the documents had been in the deletion list of the LN db already. That’s why they started disappearing again after a while!
So I had to delete everything again to make sure, rerun the copy agent again but this time change the universalid.
Took me roughly a day to fix everything, something which normally would have taken about one hour.