Plugin fails on update to add URL

I installed the addin, went to the setup page and the data entry page appeared correctly. I was able to find and select the user in the drop down list. I entered the appropriate URL as required and selected the update button. After a while I get an error message stating that the user did not exist along with reference to line 2008 of the script. It is also interesting that when looking at the code there is no line 2008 which tells me that the original code is calling another file or macro somewhere. I need help. Hope someone has a fix for this.