Help on Error Message "Excel ranout of resources while attempting to calculate one or formulas..."

Hi, I am at a lose here as I have tried everything that I could research on line. I have a file that just suddenly starting giving the "Excel ran out of resources while attempting to calculate one or formulas. As a result, these formulas cannot be evaluated". I did not created the worksheet but it does not look overly complicated but I am not much of a Excel user to know for sure?

Office365 Excel 64bit on Windows 10 machine.

I have tried;

-Disabling multi-threading

-Switched to manual calculation

-Error check formals.

-removed any images or extra data as far as I can tell.

-Modified # of calculation threads from 1-8 in Excel and same with # of processors via the taskbar.

-tried copying values only to another sheet, and still gives there error though there are formulas on the page. How that works I don't know?

-disable add-ins

Of course the person who created the file is no longer working at the company and so I wouldn't even know where to begin to rebuild it.

Any help on this would be appreciated!

Thanks

KQ