Support

The only issue you reported having is "Frontend Edit Admin User". Dale already told you how to solve it. You cannot have possibly followed his instruction and still have the same issue since the setting he told you to disable, "Disable creating / editing backend users from the frontend", is the only option which controls the only code path which can result in this error. He even told you what's going on. I have to also tell you that updating the database record of a Super User from the frontend is smelly code, as in: developers who care about security don't do this!

Then you reported an unrelated issue "Fatal error: Call to a member function get () on Boolean in
components/com_community/controllers/register.php on like 897". This is a bug in a third party component's controller. Even now, I am not sure if this is the issue you claim disappears if you disable Admin Tools. I can tell you that this issue DOES NOT come from our code, as you can clearly see in the error message. com_community is JomSocial whereas Admin Tools is com_admintools (obviously). You cannot possibly hold us responsible for code we didn't write?

Assuming that this very specific error goes away when you disable Admin Tools, it's still a bug in third party code. Admin Tools is a properly written component that goes through the Joomla! API for everything it needs from the site. It also inspects the entirety of the application input (GET, POST and cookie variables) in order to protect you. Badly written third party code which doesn't go through the Joomla! API, uses nasty tricks which only work on virgin Joomla! installations (i.e. badly written and not properly tested) or does not validate input may have its fundamental bugs inadvertently exposed when it runs in an environment that doesn't match the limited, ideal scenario its developer tested(?) it against.

The best way to figure out what's going on is debugging the affected code. If you ask its developer to debug it and tell them exactly how to reproduce the issue (maybe also give them a copy of Admin Tools Professional and an export of your Admin Tools settings) they will be able to identify the bug in their code and fix it. We cannot do that. Not because we don't know how to do that but because it requires a lot of time to get familiar with someone else's code base and in the end of the day we'll just tell you "it's definitely someone else's problem, we know how to fix it in their code but since it's not our software we couldn't possibly publish the fix". So, someone lost a full day and the problem is still there. What good would that do to anyone? Hence we ask you to contact the developer of the broken code so they have a chance to fix it and publish the fix so the problem no longer affects anyone else.

Finally note that having me spend 15' to write this does not help you or me in any way. However, if you'd spend half as much time to contact JomSocial about this issue would have very likely already resulted in a fix for your issue. When we give you an instruction we don't do it to get rid of you, we do it to help you fix your issue faster. Thank you for your understanding.