Hi,
Unfortunately not all Apps in Fusion and their modules are working as expected.
As the Photoshop API is a relatively new application, I would imagine that there have been further developments to the API since the modules were released in Fusion.
Also as the Photoshop API is a paid service, troubleshooting is a bit more complicated. Do you have purchased a quota of API calls for this? If you have a trial access, the quota was reduced to 500 calls last year. Perhaps you have already used it up?
Regards
Lars