Report not refreshing - Error Message: Sequence contains no matching element

I haven't found the cause. I was able to discover the tables causing the issue for me. 

1. Make a copy of your report file (and a back just in case) to do the work to find the table.

2. Edit the Queries of the tables. Then in Power Query for the tables you suspect may have the issue 'right click' the query and unselect 'Enable Load'
This will stop that query from loading.

NOTE this will remove all measures on the Associated table and this is why you want to do this on a copy of your report first to determine which table(s)/querie(s) are the issue?

Close and Apply, Then in Power BI refresh and see if you have the error. 
You will repeat this process turning tables on and off until you find which tables have the issue. 
For me, I turned off half of my tables. The error went away. then I turned half of them back by selecting "Enable Load" and did this several times until I was able to isolate the issue to two tables where with them on they caused the error and with them off the error didn't happen.

Once you have determined the tables you can go back to your actual file. Or make a copy again and check your work. If the tables with issues have measures. Make sure you move/recreate the measures on a different table like their own measures table and then you hopefully will be able to delete the table and re-add it fresh.

In my case, it was weird as the two tables causing the issue were a reference to another table as they were being bought in as dimensions for filtering. The original table was imported with no issue, just the referenced table had the issue. I ended up just duplicating the tables instead of referencing them as they were so small. . Only reason I had used reference was to save additional calls to the server for exactly the same query.

Hope this helps you at least locate the issue table if you run into this error. when you have 55+ tables and they all have the same error because of one table it's a bit daunting where to look.