Error Code "Excel ran our of resources while attempting to calculate one or more formulas"

This error started to come up recently on my subscription to Msft 365. The file with STOCKHISTORY function, and I put in VBA to create function "COUNTcellsbyfontcolor". Decided to Copy/Paste/Value all formulas and wipe file clean of formulas. Then I recreated the formulas. That solved the problem. BUT then the COUNTcellsbyfontcolor didn't work, and returned an error. I had saved the file as XLSB, and had to resave as XLSM, and this made the function work again. I believe Excel just "CHOKED" for whatever reason, and formulas got "corrupted", and I had to wipe the slate clean, and redo. This solved all errors.