Opening document issue with pyrevitCLI run batch

I have been trying to setup an automated batch script, but my script fails at the very beginning when trying to open the model file.

I have tried using the bare example from the docs below:

from pyrevit import HOST_APP

# __models__ is set to a list of model file paths
# __models__ = ['C:\model1.rvt']
for model in __models__:
    uidoc = HOST_APP.uiapp.OpenAndActivateDocument(model)
    doc = uidoc.Document
    # do something here with the document

but the last line fails as uidoc is always None

I’ve also tried using the DB Application.OpenDocumentFile(…) method to get a doc without a uidoc, but then I get an Exception that the “Document can not be opened”.

I can see Revit opening the file (if I run an higher version I even see the update dialog), and the UI flashes when the model is loaded, but I can never get a valid UIDocument or Document.

I have a feeling I am doing something wrong, but can’t figure out what…