SC-Login not working due unkown block of otpcheck.php

First and foremost, glad to hear it's working. As for why you need that tweak, one thing I notice on your site is that you don't have the "Include jQuery / Bootstrap" setting enabled in the SCLogin module. That setting includes a special version of jQuery and Bootstrap that is tailored just for our software. If you're loading jQuery and Bootstrap in your template or through other extensions, SCLogin will try to use them. However, there can always be compatibility issues if there are slightly different versions or other changes in the other jQuery / Bootstrap files.

So, I'd try enabling that setting to see if it works. Regardless, we'll be investigating that tweak further. It's not necessary on the overwhelming majority of sites though, which make us hesitant to just include it without a lot of research.

Of course, let us know if you run into any other issues.

Finally, if you haven't already, please consider leaving a rating and review for the SCLogin module, or our support, on the Joomla Extension Directory. It's certainly not required, but very appreciated:
extensions.joomla.org/extensions/access-...authentication/24054

Thanks,
Alex