.McAddon files and texture packs no longer work

Custom .Mcaddon files for mods, texture packs, and worlds no longer import into the game on PC. It used to be possible to click on the file in File Explorer, which would open Minecraft and place it in the correct area of the world editor. Resource packs, texture packs, etc. now behave differently—when you click them, Minecraft opens but nothing happens.

As a result, my custom texture packs, or anything downloaded from sites like Planet Minecraft or CurseForge, can no longer be imported. I only have access to Marketplace items. Attempting to manually import via file location also does not work (though I may have done it incorrectly).

This feature has always been PC-only unless you use external apps on Pocket Edition, and not available at all on console. I would appreciate if it were fixed, even though it mainly affects PC players, because as a host for console players it does allow them to use the custom packs.

I understand that Bedrock is currently experiencing many issues, most of which I can work around—except this one.