Convert Thunderbird to emClient

I am hoping someone can help. I am trying to convert Thunderbird email history over to emClient. Appears to be simple but not so.

When I attempt to do this with my gmail account I get error "Server Says “Invalid Credentials (failure)”.

Now I am 100% sure I have the right password. It does not seem to be connecting to the server properly. Any input would be great

I did this, don’t use the import of accounts from Thunderbird just manually adding them to eM Client is what worked for me.