Hi @dadel37 ,
OK so others can access the model(s) from Revit, right?
So, I also assume that the model has been workshared and are a centralised model. Is that correct?
Now if they are workshared models does everyone has access to BIM Collaborate Pro? You need to have a license of this to work on workshared models saved in ACC or BIM 360. If you have a license, then you will need to check firstly that has been active in your Autodesk Account. As well you need to have the Revit Cloud Worksharing active to allow you to use the worksharing tools.

It would also be worth having a look at this article Cannot access BIM 360 Projects in Revit from the Autodesk Knowledge Network.
I hope this fixes yours and others issue.
Please click the Accept Solution button if my reply answers your question.
Twitter: @TheDarkAsset
LinkedIn: gareth-spencer-84202532
Gareth Spencer
BIM Technical Consultant | Man and Machine (UK)