Yes, this did the trick for me! Upgraded my sit from PHP version 7.2 to 7.4 --> re-stalled W3 Total Cache and it no longer crashed my site. I think I exported my settings somewhere, so I will re-import them now and I should be good to go :)

Thanks for your help!

Has anyone found an alternative solution since this happened? My page load times are terrible now, so I'm keen to reinstall this or try another plugin

I had the exact same error lisa. I'll let you know if I'm able to fix it, but for now I'll be patient and wait for a response from support.

Immediately after re-installing W3. I've had it on my blog for a while now and no issues. It only occurred yesterday after I updated wordpress with the latest update. 

I've left it uninstalled for now so that my site can run as usual

Exact same thing for me. I updated wordpress yesterday and this morning I have the issue. When I remove the plugin my site runs okay, but as soon as I reinstall, it crashes and I can't do anything