Couldn't find query errors

The dashboard refresh came out saying there are few query errors, but when I get to open the query editor, unable to find any.

Find the screenshots below showing couple of query steps from the errors.

This is the "Added index" step and doesn't seem to show any errors in here.

This is the last step of "Reordered columns" and looks like it is taking ages to load the table (or doesn't load at all?)

How do I figure out the what/where the errors are? or Am I missing something? 

Thanks.