I was able to find a temporary fix for this (although it would likely have some side effects with applications requiring dx11). For me this issue only started to occur after I installed MSI afterburner which also installed Riva Turner for displaying FPS, temps, etc. The Riva Turner installation also installed dx11 as a pre-req. I went into my system32 and SysWOW64 folders and moved the d3dx11_42.dll and d3dx11_43.dll files to a temporary folder. After removing those files I've had no issues with running RTX texture packs and alt+tabing. I'm running version 1.16.221.
Kane McG
I was able to find a temporary fix for this (although it would likely have some side effects with applications requiring dx11). For me this issue only started to occur after I installed MSI afterburner which also installed Riva Turner for displaying FPS, temps, etc. The Riva Turner installation also installed dx11 as a pre-req. I went into my system32 and SysWOW64 folders and moved the d3dx11_42.dll and d3dx11_43.dll files to a temporary folder. After removing those files I've had no issues with running RTX texture packs and alt+tabing. I'm running version 1.16.221.