Error: There are multiple join paths between these folders

Question

I occasionally see this multiple join path error message when collapsing a field in a cross-tab report. The strange thing is that this error only occurs when collapsing on detail of the field, but does not happen when collapsing on the field title. For example, if the column is the department field, there is no error when collapsing on the department title at the top of the column. However, when collapsing on a single department (e.g. president_office) then the error occurs. The second odd thing, when reviewing the SQL there is only one join to the department table.
Does anyone have an explanation, solution, or a suggestion on how to debug this error? Sometimes I found that by rearranging the layout of the fields fixes the problem, but this is not an option in every report.
thanks

Answer 1

Since it's using the "Firstname lastname" to reference the user when I use add-distributiongroupmember, I suspect that referencing the smtp address would return different results.
Does Add-DistributionGroupMember reference AD objects, even if they don't have an associated mailbox? I ran into the same error when giving myself full permissions on a mailbox; I have only one Exchange object (a mailbox) but I have a second
AD object (user object with dom admin rights). I then went and found that the user I had trouble adding to the DG has an
AD object with no associated mailbox. (We frequently create AD users for business partners to access published remote applications.)
My suspicion is that Add-DistributionGroupMember references AD objects, and not just valid Exchange recipients. This would make sense if you're using security enabled groups and having them pull double duty - which we don't do at this company.
If my suspicion is correct, it should be documented on the technet article. http://technet.microsoft.com/en-us/library/aa995970(v=exchg.141).aspx