Important "Configuration saved. Please try again." 1.7.1 importer error with J2.5/K1.7.2 and phpbb3

This is a new K1.7.2 install in a new J2.5.4 site. I have an old phpBB3 forum that I updated to 3.0.10. All of the status info lines are green. Every time I click on "Import" I get this error:

Configuration saved. Please try again.

I tried truncating first but that did nothing. I'm using php 5.3.10

my fault - I forgot to delete the Install folder.

One more question though. All of the import went fine and I chose to create missing users autmatically but this phpBB3 is from the same site and should have the same users. After import the checkbox for "Create Missing Users" is still checked and says 0/932. I went into the Migrate Users tab and see them there also. As far as I know there should be no users to import as they already on the site.

What should I do? I'm confused

I'm not sure. Importer tries to find users that match either username or email (preferably both). The users must always be either created or mapped to the existing users. Have you tried mapping them?

Usually automatic mapping does pretty good job, but in some cases some users aren't either created or mapped. In that case you can select them manually and do whatever you want with them.