topic Can't Change Radius in Revit Architecture Forum

Can't Change Radius

MS_ARCH_PRO — Tue, 16 Mar 2021 08:28:44 GMT

I keep getting a lot of "Can't change radius" errors when using the fillet command.

In this sample, the radius that I'm trying to add is not very small. (250mm). It is driving me NUTS! It happens with almost every circular fillet.

Any ideas or hot fixes for this?

Re: Can't Change Radius

ennujozlagam — Tue, 16 Mar 2021 10:20:58 GMT

post it so we can check.

Re: Can't Change Radius

tcambare_Mesa — Wed, 13 Aug 2025 22:54:48 GMT

While you have the "Fillet" command active, look at the "Options Bar" docked below the ribbon (sometimes docked at the bottom of the interface window). There you will see a check box for radius where you can set a number. Whatever number you enter in this section is the radius that the "Fillet Command" is stating that it "Can't Change'; which further means, this is the radius that will be used to automatically complete the fillet radius on your drawing.

The TRICK is !!!! - you must check the checkbox and enter the number for the radius FIRST!

before you click (choose) the lines or arcs you wish to fillet. Afterwards, all you need to do to complete the command is press "Enter" or click within the specified radius on the screen.

If you choose the lines first before the manual entry of the radius at the Options Bar, you will still end up with the error "Can't Change Radius". See screenshot.

Re: Can't Change Radius

neyserlobraycia1 — Sat, 21 Mar 2026 14:32:23 GMT

Hello, I am having trouble with my UI.

The options bar mentioned above is missing. I looked for tutorials for how to reset the ribbon but the option bar is not mentioned there. Does anyone know how to solve that?