Specify a Language on STWB_2 ( Error Message SOTR_MESS110)

Dear friends:

I'm trying to modify a Test Plan Management with the following steps:

1. Using STWB_2 with an unique Test Plan Management.

2. Click on Modify

3. When i do that the following message appears "Speciry Languaje".

I review the following discussion http://scn.sap.com/thread/1558439,

but i don't have a solution.

Any idea?