Anyone had luck Configuring WordBB?

I've found heaps of Forums on it asking for solutions to the same question but can't find the answer anywhere. When choosing the User i get this

Default post author username does not exist on MyBB

I've tried every variation of my user name, admin, my wordpress username etc and can't get it working

 

i think you need to import the data from one database to other one. You have them on 2 separate databases right?

 

Yeah I do, but how would this fix it?

 

I knowothers have same prblem , but after this operation it worked, it is a problem of the script, or If you know php you could try to fix this if you want to use 2 different databases.