I can reach the URL without any problems using a browser or insomnia. Just not with the http connector.
What can be the cause of the -1 error code, or, where do I look for the problem?
Best answer by Vincent Doppenberg
The problem is most likely that your GUI is quite old. That version of the GUI still targets version 4.5 of the .NET Framework, which means that it will have the problem that I described earlier. Updating your GUI to the newest version, which targets .NET Framework 4.7, should fix this issue.