Do you have a problem with a final sequence ? Your outro is freezing ?
In this case, I found a solution.
The reason is the atmosphere.
For example my own case :
I made some kind of atmosphere in the media tracker. But, I did not like my work, so I removed all the effects so there was nothing left. BUT! In the mediatracker's main menu you can see that the atmosphere is still created.
Therefore, if you have the same problem wit feezig outro, just remove the atmosphere sequence in main menu of mediatracker.
Important: When you remove the atmosphere, you can update the map without problems because the UID is not changed.
This error occurs only when you run the trackmania using click to gbx file or if you start the track using install & Play.
If you test a track with trackmania browser , this error does not occur.
It is likely that the outo first seeks the atmosphere, because the atmosphere is visible as created , but because there the atmosphere none , the outro freezing.
Maybe it will help somebody