Improvement is needed. I just spent 3 weeks also with outside IBM help trying to get the EDUCHAN.sar demo working using the July version of the open beta. Both of us worked, unsuccessfully, on solving this problem during that time. The problem turned out to be insufficient permissions to the .../services directory containing the .sar file.
The reason it took 3 weeks to solve is there were zero error messages anywhere pointing me to the fact that this was a permissions problem. I'm running the code embedded in Liberty under CICS/TS 5.3. I could tell that the feature wasn't finding and picking up the .sar file from the lack of associated messages in the server's messages.log file. Problem is, there were also no messages providing any clue as to why.
Note: We are not using any sort of SAF-based security product for USS files and instead are running with "permission bits" only, so there was also no opportunity to detect the problem from any sort of SAF security message.
The lack of any meaningful error messages turned what should have been at most a 5 minute problem into a 3 week one that only got solved by accident.