If you are attempting to load a family into your project and you get a message that says "Cannot Load Family Files"; it's due to what family template and/or what family category the custom family is set to.
For example you have a diffuser family that would be loaded by going to the Systems tab on the ribbon and clicking on "Air Terminal" then click on "Load Family" and navigator to your diffuser. If you get the message "Cannot Load Family Files" this could mean that the diffuser was not created with the proper family template file and the family category was not set to air terminal.
Here are just a few places where you can load a family into your model;
- Systems tab > HVAC, Plumbing and Piping or Electrical
- Architecture tab > Build, Circulation or Openings
- Insert tab > Load Family
- Annotate tab > Symbol, Component
- Massing & Site tab > Site Component, Parking Component
If you are unsure where to load a family into your Revit project you can do so by going to the Insert tab > Load Family > navigate to the family you would like to load and click the Open button. This will make the family active and you can go ahead and place the family.
The only problem is now your family is in your project but you do not know what type of family it is. If its a device I am going to assume that I will find that family by going to the Systems tab > Electrical > Devices. But if the family wasn't created using the device family template then it will give you the error message above.
You can go through several places to try to load the family or you can simply open the family and look at its Family Category and Parameters from the Create tab > Properties panel.
The family category will indicate what type of family it is and this is where you will load it within the project. Close the family file.
In your project you now know you can load the family as a Mechanical Equipment from the Systems tab. If the family is not already loaded and showing in your Properties > Type Selector then click on the "Load Family" tool from the ribbon.