SharePoint 2019 Site Contents is broken after installing the 2021 February Cumulative Update (KB 4493194)

Question

After installing the February 2021 CU (KB4493194) on a Microsoft Server SharePoint 2019 VM, the "Site Contents" page is broken on the non-classic (online) experience. There is a script error on the Browser's debugger tools as follows:

Uncaught RangeError: Maximum call stack size exceeded
at e.errback (require-dev.js?rev=d9ZmVmtligCBNmdHqXaXzQ%3D%3DTAG0:1)
at require-dev.js?rev=d9ZmVmtligCBNmdHqXaXzQ%3D%3DTAG0:1
at require-dev.js?rev=d9ZmVmtligCBNmdHqXaXzQ%3D%3DTAG0:1
at each (require-dev.js?rev=d9ZmVmtligCBNmdHqXaXzQ%3D%3DTAG0:1)
at emit (require-dev.js?rev=d9ZmVmtligCBNmdHqXaXzQ%3D%3DTAG0:1)
at e.<anonymous> (require-dev.js?rev=d9ZmVmtligCBNmdHqXaXzQ%3D%3DTAG0:1)
at e.errback (require-dev.js?rev=d9ZmVmtligCBNmdHqXaXzQ%3D%3DTAG0:1)
at require-dev.js?rev=d9ZmVmtligCBNmdHqXaXzQ%3D%3DTAG0:1
at require-dev.js?rev=d9ZmVmtligCBNmdHqXaXzQ%3D%3DTAG0:1
at each (require-dev.js?rev=d9ZmVmtligCBNmdHqXaXzQ%3D%3DTAG0:1)

The site was working fine with the April 2020 CU, and it only broke after installing the new February 2021 CU.

Is this a known issue, and if so, is there a fix for it?

Best Regards,
Ahmad Nassar

Answer 1

Remember you need to apply two patches per month (or when a language update isn't released, the most recent previous update). Make sure you've installed https://support.microsoft.com/help/4493193 and then re-run the Config Wizard.