Similar to above, I was playing the default SFMM scenario, and wanted to update it by building the missing rides (it was easier to just start with the default scenario).
Using 8 car, I used "own all land" so as to make enough room for me to build rides. Eventually, I restored the border fence, but it did not appear in the normal spot, and is now blocking the entrance to the park. If I remove the border fence again, it disappears, but the guests trying to enter the park will not walk past where the fence was (right in front of the entrance gate), so nobody can enter the park. Guests already in the park can leave, however.
Inverting the land ownership created all sorts of glitches. I tried moving the guest entry point to inside the land that I owned, but instead of walking into the park, the guests stack up on the square that I selected as the entry point and cannot move.
Not sure what else to do other than start over, which would be unfortunate. Thanks for any help.