Gotcha, in that case I moved this conversation to the Bugs section. If you have anymore information, please add it here to give the AE team the best chance of reproducing the issue.
Did you follow the instructions in the error to install the Cineware plug-in?
On the After Effects page in the Creative Cloud Desktop app, click the overflow menu (three dots) and choose "Add-ons," then see if Cineware is already installed. See the attached screenshots.