Symptoms
Users are seeing this error in the following scenarios:
1. When opening and editing workflows
2. Clicking on "SmartObjects" in the top toolbar when navigating their workflow in K2 Designer.
Diagnosis
This seems to happen after Appit 1.5 Update 6.
Happens on multiple applications, multiple users, and on all browsers.
Most users can click "OK" and it should not have much effect. Users should still be able to use Designer, and deploy workflow solutions like normal.
Solution
This was found to be a bug.
A coldfix for this was created. If you are seeing this behavior, please contact K2 Support for this coldfix.