Frequently Asked Questions

When I enter my serial number into R20 it works, but if I quit and reopen it, it still says it will expire.

The issue has been resolved with the latest installers, but on macOS Sierra or High Sierra, there was a bug where the temporary serial number could not be overridden with the permanent one.

If you downloaded the installer within the first two weeks of release chances are you will experience this.

You have one of two options:

  • Remove the MCA and MCN files and then serialize Cinema 4D when prompted during the launch (instructions are below on how to do this process). This is the fastest and most reliable fix.
  • If deleting the MCA and MCN files does not work for you, you can try uninstalling Cinema 4D, going to /Users/**USERNAME**/Library/Preferences (use Go > Go To Folder in Finder for this and replace **USERNAME** with your user account's username) and deleting the MAXON Folder as well as the MCA and MCN Files, then re-downloading and re-installing Cinema 4D.
Instructions on removing MCA and MCN files:

First, you must go to this file path(which is a hidden folder):


If you do not know how to unhide folders, open a finder window and hit Go > Go To Folder and paste that path in the folder search bar.

Before the next step, it is very important to make sure Cinema 4D is shut down.

Next, you will delete all your 20mca and 20mcn files. This is where your serial numbers are stored in the OSX filesystem.

Finally, launch Cinema 4D. You will be prompted to enter your serial number again. This time use your permanent registered serial number!

Please Wait!

Please wait... it will take a second!