Bug was related to windows .net c++ framework, or something of that sort.
I thought only I was facing this problem but after I restarted my pc, then reinstalled Minecraft windows 10 edition, then rebooted the pc again but still same problem, then I decided to report this bug too.
some seeds do not have a portal room generated in the stronghold. My friend uses addons to xray and look for endportal tiles and sometimes there isn't one in some of the strongholds we looked in, but you can use chunkbase.com to easily search for the many strongholds that generate in the world using the seed.