Changing of user accounts results in request error.

[GrumpyBear2014 0]

Have been getting numerous errors of this sort.  "Error.  There was an error processing the reuqest." On the error page there is an OK button.  Using a remote's enter it will go away, but then quite often followed up with may more of the same error.  But these ones do not have the foucus on the OK button so have to find a mouse and click on the button.  Have been able to track in down in the log files, which I have attched.  It seems to be a 500 error on the server, but not know what the request is, I have no way of fixing it.   

theater-63591229823.txt