You simply have some data on your clipboard and AE is trying to interpet it from using another program. Nothing to worry about.
Mylenium is very likely correct.
In the future, when asking questions, please provide more information so that we can better help you.
What version of After Effects? Have you installed the recent updates? What operating system? Has this ever worked before? What other software are you running? Do you have any third-party effects or codecs installed? Tell us about your computer hardware.