A section dedicated to error messages and debugging

I see a lot of questions from people that comes clearly not from the programming world, saying they can't access a node or they get "Attempt to call function X in base 'null instance' on a null instance", they may waste a lot of time just because is not clear that the message means a variable is null.

Another cryptic even for programmers are the "Condition det==0 is true" and others like this.

So, a list of common error messages could be helpful.

A tour around the debugger to know the available tools to track errors and other things could be in the same section too.