New error old data connections

[clausbock]

After a deployment to the system where I get my data from, I get below error on many of my connections:

Expression.Error: We cannot convert the value <ccon>null to type Table.. </ccon>. The exception was raised by the IDbCommand interface. Table: XXX.

The only thing that was changed in the deployment was the option to add a new parameter to the requests to filter the response differntly.

Since I don't beleive that it has anything to do with the adding of the parameter option, I hope to find out if it could be some other server side setting that been changed that makes Power BI look differently at the privacy setting for all the connections to that system?

NOTE:

1. The errors happens even in older workbooks that doesn't use the new parameter.
2. It seems to be associated with the use of Merge and Append.
3. The error doesn't happen if I disable privacy and run it in the desktop app.