Can't assign issue type to workflow

[ivours]

Hi,

I was trying to assign an issue type to an existing workflow (in an active workflow scheme), but had no luck. When I try to do it from the project administration, I get the following error:

Ok, then I tried from Administration -> Issues -> Workflow schemes and it does the job. But when I go and check in the project, I don't see the changes reflected.

I also tried to disable and enable calendar plugin as detailed here but had no luck.

Do you know anything else I could try? I can't try rebooting the instance because it's in a production environment, used by a lot of people.

Thanks in advance.