NAV2016:Encryption cannot be reactivated after SQL restore

Hello,
I've a sql and NST on one machine. I used the NAV integrated Encryption Management. I exported the encryption key...
This server crashed :-( So, I installed a new server, created a new NST and restored the database on it (SQL restore).
It shows up that the encryption is enabled in that DB. (but not encryption key)
Now, I try to import the encryption key. By importing the key, It tells me it will decrypt and recrypt the data, ok so far. Then it hangs with error "unable to encrypt data. The provided string is toot long".

I tried to create a Cronus DB, import the same key there (worked), change the database and restart the service but it looks smarter that that

Actually some of my data are unreadable What's wrong?
Thanx for support.

Chris