Import Multibit multibit.key into Electrum Have a multibit.key file from an old Multibit Wallet, but can't import it into Electrum. 

When I copy and paste the char string from the file into the "Import Addresses and Private Keys" Electrum window it just never allows me to push Next and proceed. 

What am I doing wrong? Is there any other way?
I had the same problem with one of my customers and found out that Multibit had generated an invalid key due to a bug in the software. This key cannot be used because it is out-of-range of the bitcoin EC specs. Check if your key is working with any other software. We are currently working on a solution - you can PM me.