Welcome to the Excel Community

What has happened to Excel??

I used to be able to create a workbook with several external data connections, several tables with calculated values, numerous queries to Power Query, and multiple sheets with lots and lots of calculations and data.  All this used to work fine in a single workbook for complex business models.

I'm using this version now:

Microsoft® Excel® for Microsoft 365 MSO (Version 2512 Build 16.0.19530.20184) 64-bit

I can't get past three external connections, a few tables, and maybe 12 calculated columns on a single sheet without Excel continuously crashing.  Excel used to be a workhorse, now it's not even acting like a pony for a kids party.  I've tried using both .xlsx and .xlsb files, turning off automatic calculations and whole bunch of other stuff.  I've rebuilt the file 4 times using different approaches and get the same thing on different computers.  My work computer and my personal computer does the exact same thing.  This is a model that has run like a champ year after year for about 12 years and now I can't even filter without it crashing.

I know it's Excel because when I build it new, it works great up to about 12 calculated columns then starts crashing.  When I take an existing model it will only start working after I strip a whole bunch of stuff out and reduce the number of calculations.  These files worked great last year at this time.

Has anyone else experienced this with newer versions of Excel?