Hello @gcincilla ,
We reached out to the extension owner and have confirmed that updating them for AP 5.1 is planned, but is not yet underway. The current extension URL [1] for 5.1.0 seems to be placeholder.
However, I did install the 3d-e-chem extensions in AP 4.7.6 yesterday as shown in my post, and it completed successfully.
If you are not on 4.7.6 (maybe an earlier version?), let me know what version you are on.
But as long as you enable the Community Extension site (Experimental) in the update sites preferences, it should work.
Is there any additional information other than “Cannot perform operation”? Any logs with additional error info?
Thank you,
Nickolaus