Win10, version 0.15.1 MCPE, no mods/textures (stock). Intel i7, with nVidia 760Ti updated to most recent drivers. For what it's worth, I just rapidly logged into my son's admin account, disabled the Ethernet adapter manually so the computer was offline, and the game appears to launch correctly, although I didn't wander about in a world for any length of time. I re-enabled the Ethernet adapter and relaunched the game, and it made it to the title menu, then froze for about 15-20 seconds before crashing to desktop. A further re-launch won't even get to that point.
In my case, definitely seems that internet access is a key indicator on sub accounts other than the primary account. However, not sure how to script disabling network access for now so kids can keep playing.
Yes - already tried that. I made both of my 2 children's accounts admin accounts, still will not work. Also created a new temporary local account (not tied to a Microsoft account) as an admin account, and it would not work. Also attempted to grant full access rights to the package directory within ProgramFiles subdirectory to all user accounts with no resolution.
Most recent exception log shows a fault in twinapi.appcore.dll, under version 0.15.1.0 of Minecraft.Win10.DX11.exe. Parallel error log seems to indicate something with combase.dll. The WER report doesn't show much information that looks useful, besides reporting the friendly event name as "Stopped working", and whether useful information or not, a State[0] key/value pair of "Transport.DoneStage1 / 1 (true?)".
Similar launch bug for me on Windows 10 Beta. Game will randomly crash during launch, usually during white Mojang splash screen, sometimes rarely makes it to the main menu and then crashes. Only happens on non primary accounts on computer - runs fine on my primary account. Dxdiag shows no problems, which seems correct since the game runs fine on primary account. Based upon proc monitor logs, crash appears to be randomly happening...no two or three crashes happen at same point in app loading process.
The comment by rplatham is difficult for me to see if it applies to Windows 10 Beta edition. I tried loading the game without a network connection, which worked to load the game, but there doesn't appear to be any menu option under "Options" to sign out of Xbox Live. I see menu options to "Manage Xbox Live", and "Gamertag", but neither of those reference logging out of XBox Live. In addition, neither of those even load when not on the network.