Help with armory wallet

Hi all. A relative of mine passed away recently and I was charged with going through his stuff. On the computer I found the information for a bitcoin wallet on armory. I don't know anything about bitcoin and I have been trying to read about it for the past two weeks to figure out how to access any funds that might be available with no luck.

I have downloaded the latest version of armory and bitcoin core but when I access the wallet it does not show any funds, the balance is just "(…)". Since I downloaded bitcoin core I think armory is online but it is stuck on "preparing databases".

I read that I could "sweep" the funds into another wallet service like electrum so I tried to do that but when I input the privatekeys the "next" button is still greyed out and I can't move forward.

Apologies for any bad english, it's not my first language. Any help would be truly appreciated!!