@MaxonL16591286 Can you check the particular attachment category rulefor any privilege if that privilege is available for Access group A and not access group B. If that is the case, that could be the cause for the issue.
Even I hardcode the when rule to always true, the problem still exist. Per trace, seems Pega try to locate the when rule in base class, however the when rule is defined in case type class.
Also, if I call the when rule directly from a DT defined in case type class, it's normal, no issue found.
So the issue can be refined as below. Appreciate kindly help soon as we need solve it urgently. Thanks!
Under some access groups, a when rule used by a attachment category is inaccessible when Pega need to call it for the attachment category access. Seems the direct reason is Pega try to locate this when rule in base class which does not exist. The when rule is defined in case type class.
Under other access groups, this issue does not happen, every thing is normal.