Impossible to synchronize

Hi! Both my Anki desktop and the mobile version told me the deck collection is too different to be merged. So, I chose the collection, which I wanted to keep and assumed there would be no longer problem with the syncing. However, this message welcomes me every time I open the Ankidroid or click on the sync button on Anki in my pc. I chose one of the collections to keep and the other to delete, yet the problem is not solved. Any idea what I can do?

To get things back to normal, you must choose Upload on one device, then Download on your other devices.

Thank you very much, it helped.