Query error prevents opening Power Query to fix the error

Hi There, I know this is an old post, but I happened upon it when I made a similar mistake in Excel. I got locked out of PQ editor when trying to adapt a VBA function that updates PQ text parameters, to work with a date parameter. The script wrote a date value into a 'Type = ' parameter in the query string, and I got the 'Frown' error message whenever I opened the file, or tried to edit a query. 

Because I caused the problem with VBA, I was able to resolve it by running the same script, but replacing the date value with a valid 'Type =' parameter value. I can see you were using pBI so VBA wouldn't have been an option for you, but wanted to share.  Not sure if there is another scripting language or approach that can get at a parameter query string in a pbix file.