Unhandled exception in power query

I'm am usng Exxel 365 and have been using Excel to connect to a data souce on Google sheets with power query. It has been working OK. I have had to change the sheets data souce a couple of times and managed to accomplish that wth too much drama.Today, I needed to change the sheets data source again. I loaded the excel file (currently working and updating sucessfully). Before any changes were made, i went to the to the Data and Connections I see my 2 queries. If I try to click on connections I get message about unhandled excption from .NET framwork. It says an Arithmatic operation resulted in an overflow. It offers 2 choices "Details" or Continue. I have tried both but excel is locked up at that point is to kill the .NET framework running under excel in Task manager. I have tried rebooting, running excel in safe mode, and closing any other running programs. Nothing helps.

Again everything still works in excel including updating the data source. The only time I get the error is when I attempt to begin to change the source address. I never get that far. Any ideas would be appreciated