“Invalid column unit type” in Revit 2021+? Here’s why — and the 1-click fix

If you upgraded a family to Revit 2021, 2022, 2023, or 2024 and it suddenly won’t load, throws “Invalid column unit type,” or the type catalog is just silently ignored — you’re not doing anything wrong. Revit changed its rules, and your old type catalog file is still speaking the old language.

Here’s exactly what happened and how to fix it in under a minute.

The symptom

You try to load a family that has a type catalog (.txt) file alongside it, and you get one of these:

• An error: Invalid column unit type
• An error: Could not parse column header
• The family loads, but none of the catalog types appear — Revit quietly skipped the file

This only started after moving the family to Revit 2021 or newer. The same file worked fine in Revit 2020 and earlier.

The cause: Revit 2021 renamed its unit keywords

In Revit 2021, Autodesk reworked how the program stores units internally (the move to ForgeTypeId). As part of that, dozens of unit keywords used in type catalog headers were renamed.

Type catalog files are plain text, and the header row tells Revit the unit for each column — things like ##length##millimeters or ##flow##gallons_us_per_minute. Revit 2021 no longer recognizes the old names, so it rejects the whole column — and often the whole file.

A couple of real examples:

There are many more like this. One wrong keyword anywhere in the header is enough to break the load.

Fix option 1 — Edit the file by hand

You can open the .txt catalog in any text editor and rename the outdated keywords to their 2021+ equivalents, then save. This works, but:

• You have to know every renamed keyword (there are dozens).
• One typo and it still won’t load.
• It’s slow and error-prone if you have many catalogs to upgrade.

Fix option 2 — Convert it automatically (free, 1-click)

We built a free Family Type Catalog Converter that does exactly this. Drop your old .txt catalog file in, and it rewrites every outdated unit keyword to its Revit 2021+ name based on Autodesk’s official list of changes — instantly.

A few things worth knowing:

• It runs entirely in your browser. Your file never leaves your computer.
• It only touches unit keywords it recognizes — everything else in your file is left exactly as-is.
• It’s free, and there’s no account — just an email so we can send you the converted file.

Open the free converter →

Heads up: run the converter on your pre-2021 catalog files. The output uses the new unit names, so a converted file will not load in Revit 2020 or earlier.