We had a small widget that allowed customers to share records that were set to a private sharing model in our community. Everything was rather simple and it would simply allow them to select users that were visible via Sharing Sets and create an __Share record in APEX.
I've been reported recently that an error is thrown but only on the community side of things. Nothing seems to be working where it was working. We are using Customer Community Plus licenses.
The error being thrown is : System.TypeException: DML operation INSERT not allowed on <Object>__Share
which seemed to indicate access not available on the object. That seems odd because they are able to interact with the object just fine in order to create/edit/delete them.
I looked up the Sharing Model (its private both internally and externally), I looked at the profile and their access and the sharing sets in the community. Like I said, they seem to interact fine with the objects when it comes to seeing the records and their right.
Additionally, standard license users can use the component fine and also share with community users without a problem. They also see the records as expected.
Am I missing an update or something that seem to make it so this doesn't work anymore? Anyone having trouble with this or encountered the same problem?