So, I've made some progress by using AndrewZ's instructions above (his instructions were posted on a GoDaddy forum, BTW) located here->

https://forum.hostingmetropolis.com/user/Discussion.aspx?id=61172

I'm hoping my final hurdle is to resolve the (original posted) null not allowed issue, and now displayed on my site too, follows:

Unhandled Error

Error Details

I've posted a similar question on GoDaddy's DNN forum as well (https://forum.hostingmetropolis.com/user/Discussion.aspx?id=128093).  I've searched the DNN website's forums, and one recommendation was to purge (truncate) the EventLog table in SQL, which I did (it has zero rows in it now vs 968 before-hand). Unfortunately, this did not resolve the above error.

There doesn't seem to be any clear information anywhere on what exactly in DNN causes it to throw this error, i.e. in order to focus my 'investigation'.

Has anyone here encountered this before and resolved it (other that purging the Eventlog)? Can anyone suggest where I might look/investigate?

I'm a volunteer web admin for a non-profit organization, so any pointers would be very much appreciated. I'd really like to get this new content live in the next day or two as there is an annual charity fundraiser planned for this organization next month.

Thank you.

Jack