Error when trying to combine files

Hi

I have been tying to combine files in a SharePoint folder through Power Query. 

When I get to the Combine step, to expnad the binary files I get the eorr 

Have tried savign the files as CSV also, the erorr message still pops up. 

Is there a bug? BEcause I have repotrs I run that's set up this way and they are fine. It's just any new reports I try to set up doesn't seem to work. 

Thanks