GetMyEbaySelling Stopped working

[walmisi0]

Hi, my former client is using SOAP API, and yesterday GetMyEbaySelling ceased to work, with message:

"The API call "{0}" is invalid or not supported in this release."

Anything changed ? Anyone has a clue ? he is using the same code for years.

thanks in advance

[walmisi0]

Update: The same call works correctly on sandbox.