so i was in my tardis, rematerialized, (btw it took me a week and 3 weeks to make) and went to spawn. then i tried summoning it and it said: Cannot summon Tardis whilst in flight. PLZ FIX also i deserve something for 10 days of my time wasted :/
I'm assuming your interior was a custom one, so just place down a new Tardis and do the /tardis-interior-pos x y z command.
It's pretty common knowledge between users of the Dalek Mod, just make sure you have the exact position of your interior. (Do F3 and take a screenshot)