The files displayed in the model tree of BIMcollab Zoom can have the following colors:
Black = loaded model
Grey = model file found, but not loaded. Right click the model, and choose Load model if you want to show the model in BIMcollab Zoom
Red = model file not found. Right click on the model and choose Select file to find the model file
When multiple model files not found (due to relocation of model files, or opening the project on another computer) you might have to only select one file again, since all other missing model files will be found at the new location.
📝 Note: When working with a shared project folder, the red color can also indicate that the path of the shared folder is incorrect. To fix this:
Go to File > Project folder...
Click the "..." button
Navigate in the finder to the correct project folder and click OK
Click on 'Share'
For more information on how to set up a shared project folder in BIMcollab Zoom, read the article Set up the Project folder to link shared files to a project.