This release has been the most beta tested and automated test we've released. Honestly, in the last week (since it's been available) we've had less support requests than during any other release period and there hasn't been any critical issues requiring a SCLogin v4.1.1 or JFBConnect v6.1.1 release yet. We still have a bug-fix rollup release planned, likely for next week, but no widespread reports of issues yet.
As for your current issue, the error you're getting is because you have a template override for the SCLogin module in your /templates/<YOUR_TEMPLATE>/html/mod_sclogin folder and that override is calling outdated code from the previous release. We removed the getForgotUser function call from the template files to make future overrides easier. Without it, there's less 'code' in the template file and it's much more straight HTML as it should be.
With any update to any extension, if you have template or function overrides for the extension, you will need to update those overrides with the code in the latest release.
If you're unsure what I'm talking about above, the easiest 'fix' is to simply rename the /templates/<YOUR_TEMPLATE>/html/mod_sclogin folder. That will remove any overrides you have on your site and have SCLogin use the newest output files that were installed with the latest release.
SCLogin v4.1.0 has many, many compatibility updates and general fixes. If there are any specific overrides you need for your site, please let us know what they are so we can consider including them in a future release.
I hope that helps explain and answer your questions.
Thanks,
Alex