Dimension Set Query Issue

Hello,
I'm not sure what happened but a query I created on sales order line and dimension set entry no longer works.

It looks like there is a problem with the dimension set entry table as I created a new query on just this table and included all fields. when I run the query I get the following error message.

"the definition of the test query has changed. Start your activity again" which is the same error I see on my sales line query.

Has anybody seen this before? I would really appreciate some advise on how to resolve this.

Thanks