I recently created a fresh Singleplayer Creative world to build a custom TARDIS Interior for fun. After spending about an hour building inside the TARDIS, I found that I was unable to exit the TARDIS from the inside. The only way to leave is use the /kill command.
Here's a video showcasing the issue: https://youtu.be/AHZwRnuXybI
I'm on the 1.12.2 version of the Dalek Mod and the recommended 1.12.2 version of Forge. No other mods are installed.
(Edit: Something I should note is that I have not been off-world with this TARDIS. I literally created a world, spawned a blank TARDIS and started building. When I was about finished building I tired to leave, thus discovering the issue.)
(Edit 2: I think the world is just busted. Trying to thinker around on the world a bit more to figure out how to fix things myself, I found I was able to summon my TARDIS while already inside my TARDIS. I don't think this is intended behavior, so I'm guessing the world itself is just bugged.)
I presume the TARDIS was landed and it was saying you cannot exit the TARDIS in flight?
No. Right-clicking on the door doesn't give any message and doesn't open the door. Using Door Controls does make the door physically open, but it doesn't allow me to leave. I walk into the door and it does nothing. No messages, nothing. You can see my issue in a bit more detail in the video I linked.