The Jetways are the only part of the scenery that are not controlled by any of our software modules, which is why when our software modules are not running for any reason, the only thing that remains are the jetways. This means your problem is not related in any way to the installation or a problem with the FSDT sceneries.
The only thing that could result in a jetway disappearing, it's another AFCAD from another product in conflict.
As discussed many times on the forum, to find conflicting AFCAD duplicates, use the free FSX Airport Scanner program.
