Created new world (creative, cheats enabled.) Included a behavior pack and two resource packs, but these are actually the vanilla packs from minecraft.net (was planning on editing them later to create my own add-ons.) No changes have been made to these packs yet.

Loaded world. Opened creative inventory, selected building blocks from first inventory tab (yellow concrete, acacia planks, stairs and slabs.) Selected next tab (decorations) to find the next item I needed, the acacia fence. Don't see this in inventory, can only see three lines of items, but before I can selected another tab, crashed to desktop. No error message.

Started MCWIN10 again, loaded same world. yellow concrete and torches are in hotbar, but not the other items selected before. Selected the acacia items, went to decorations tab. MCWIN10 crashed to desktop again.

Started MCWIN10 again, this time created a new creative world with no packs. I do get the full decorations tab and can see the fences, no crash. Will try to refresh the packs to make sure they are vanilla and up to date, to verify if the problem happens with resource packs.

UPDATE: Replaced all files in the resource and behavior packs (except manifest.json) with the files in the vanilla 1.1 zips. Reloaded world, confirmed the issue was the same. Compared my manifest.json files to the example in the new zips to make sure it wasn't something stupid on my part like a version change, but everything looks correct. These packs did load fine before the update, since the only changes I'd made was to give them unique UUIDs. I haven't started editing any of the other json or texture files.