Strange error with constraint

[backerst]

Hi, everyone.

I have several subprocesses. In one of it I have 2 diverging gateways. This gateways check if a string variable is equal to any of the string constants.  The first of gateways works excellent. But the second gateway works very strange.

This is a fragment of process with second gateway.

First, I set up constraint (sorry for different languages on screenshots):

In script tab it looks like this:

I click the OK button. After I re-open constraint editor and it looks like this:

There is no field with constant for comparing. And if I try go to Script-tab, I get this error (sorry for language again):

In English it is like this:

"Error while generating script:

Could not generate expression for script. Enter the correct form parameters.

Check the entered data in the expression editor."

With "Confirm" sequence flow I have the same behavior.

But in other sub-processes and in this sub-process under this workitems I have very similar workitems. And they work!

Any suggestions, why this is happening here?

P.S.: jBPM 6.5.0