Cannot launch User Import Tool, error crashes the app.

We use this tool every few months without any issues. We have started receiving an error a few days ago when the User Import Tool program starts. The app closes after the user clicks OK to acknowledge the error. We are not able to use the program due to this error. The program is running on a Windows 10 Dell Latitude 7400 laptop and we have tried a fresh install on two other Windows 10 devices with the same error and result.

We have tried multiple troubleshooting methods but are not able to resolve the issue. We have re-installed the application, rebooted the computer, and ultimately we installed the tool on a couple of other machines and we experienced the same error.
After digging deeper I believe I have found a bug in the application that is causing it to crash. I think it is related to the app attempting to communicate with the AdButler API and receiving a null response. Could someone please assist us in resolving this issue?
Here are the steps I followed to trace what I believe is the root cause of the error.
1. I began digging into the error and could not find anything in search results matching the error. I also verified that UserImportTool.exe has been added to Windows Firewall and allowed access to the network. I also disabled windows firewall.
2. I inspected the windows application log and discovered several related UserImportTool.exe errors.
3. UserImportTool.exe shows it is encountering a .NET Runtime unhandled exception. The UserImportTool.MainWindow.UpdateAdButlerBanner call is encountering a NullReferenceException. See the screenshot below.
4. I used Wireshark to inspect the packets sent. USerImportTool.exe is making a call to the AdButler API and the app appears to be receiving a payload with a null value which isn't handled by the app. Causing the crash.
Parents Reply Children
No Data