Shabnam Watson shows us how to change the connection string in VertiPaq Analyzer, a plugin for Excel:
While trying to set up VertiPaq Analyzer on a new computer, I ran into a problem where Excel was not letting me change the SSAS connection that was built in the workbook. It turns out I had missed one of steps in the instructions in the workbook. As a result, when I got to Connection Properties, everything was grayed out and this message was at the bottom:
Some properties cannot be changed because this connection was modified using PowerPivot Add-in.
Read on to see how to fix this. And check out VertiPaq Analyzer if you’re working heavily with Analysis Services Tabular or Power BI.