Why am I not able to update an Issue?

[Frank Blessing]

Hey there,

while trying to update my issue I get the following error messages.

[INFO] [talledLocalContainer] It seems that you have tried to perform a workflow operation (Create) that is not valid for the current state of this issue (XYZ). The likely cause is that somebody has changed the issue recently, please look at the issue history for details.

The second sentence suggests that something about the issue must have been changed or similiar, but I'm not aware that something has changed.
I'm reading HTML Mails to get the information on the Issue. The first time an email is read it should create the issue in the manually created project(if not already exists). The second time it reads an email on that issue it should update the issue.

The creation of the issue out of the email works fine.
The error only occurs if I try to update the issue.

Thanks in advance for any input on this.

[Frank Blessing · Accepted solution]

My fault.
I was using TransitionValidation instead of UpdateValidation.
 

[Nic Brough -Adaptavist-]

That sounds very broken.  You shouldn't be able to call "create" on an existing issue at all.