Others have had similar problems, and I've read through those threads but none of those solutions have worked yet.
The ship is assigned to me.
I am standing on the same square.
I have assigned myself to the crewlist (with confirmation message)
I can view the ship crewlist and I am on it.
I have cleared my cache as well
But: I still cannot enter the ship. It tells me the ship doesn't have a door to enter.
I have had problems sometimes, but refreshing the page usually does the trick, then clicking the enter button on the left of the travel screen, which should show the "friendly ship as an option to enter.