Hello,
I have a plugin here that ran error-free until 2023 R3.
Now with 2024 R2 and also with 2025 R1 I get this error message:
“GET Unexpected statuscode BadRequest in ‘http://demoServer/API/rest/v1/eventTypes?disabled’ - Unrecognized Guid format.”
I have found out that it is due to the background plugin, because if I comment out the background plugin in the plugin definition, the management client no longer crashes.
Our plugin is based on the Sensor Monitor sample plugin. This plugin runs without any problems. I have compared both plugins and adjusted supposed differences accordingly, but this was not successful. I have tried everything possible, such as changing the Guid, but everything I have tried has not worked. I can still see and edit the plugin in the Management Client, but as soon as I try to look at the cameras or the recorders, for example, I get the error message mentioned above.
I am currently going round in circles and have no idea what could be wrong.
Many thanks in advance for your answers 
Do you build your plugin using the newest MIP SDK NuGet?
We have a hunch or wild guess that there might be something wrong in the ItemManager and the GetKnownEventTypes. Try to inspect and see if there is something that might be a bad Guid or similar.
As this is a wild guess it might not lead to a solution. In that case we have an idea that we would be able to best help if we could see your plugin. Is it feasible that we could debug it in the Milestone test lab? We are hoping that it does not require special hardware or similar to be able to test, if it doesn’t please let us see the source code project.
I suspect you might want to upload it to Milestone Support rather than sharing it on this public forum, for that reason I took the liberty to create a support case in your name - MSC2061191.
Bo, many thanks for your support.
The hint that the eventGroup collection is missing in the return of “GetKnownEventGroups” was great, in the older versions this did not lead to the error.
public override Collection GetKnownEventGroups(CultureInfo culture)
{
return new Collection() { eventGroup };
}
Many thanks 