Every time there's an update one must struggle several days or weeks before he can get the bitcore wallet to update and run successfully, and this is very sad.

I updated Bitcore wallet twice now. from version 14 to 15.02 and now from 15.02 to 15.03. Everytime it was super simple and worked like a charm. It was on windows though, but that is what 90% people will use.
I updated bitcore wallet twice too. And it was versions 14, 15.2 and 15.3. And everytime i had an issue with syncing. The Wallet was closing when syncing was almost done. I had to delete all data and resync all blockchain to solve this issue.
Dev told me that after version 14 the blockchain compression method was changed, and resyncing was necessary. What's happened with my wallet (or the blockchain) when dev released version 15.3 i do not know, but even the 15.2 version was giving me the error when i tried to run it.