In Amesim it is always possible to open a model from a previous version, update it, and run it in a more recent version. This process is managed by the Updete Model Assistant.
Unfortunately, you incurred into a problem of version 16.0 that has already been identified and corrected for version 16.1. This problem concerns the customized submodels of the hydraulic resistance library, namely the bends at 30, 45, 60 and 90 degrees.
A possible solution would be to replace these customized components with the generic submodel (for example HR232) in the model in version 1520 and then update it to version 1600.
I will let you know if I come up with a better solution.