Hello @Nalani ...
Since we cannot see what content you were trying to import from Commons, this is a little tough to diagnose here in the Community. But, I am going to take an educated guess on what might be happening. You mentioned that part of your error message had the words "external tool" in it. This leads me to believe that whoever originally shared that content to Canvas Commons was using some kind of third-party external LTI tool that was integrated into their Canvas environment. But, if you got that content from someone at another school, it's quite possible that your school may not have that same external tool installed in your own Canvas environment. Further, even if the LTI was installed at your school, the link may need to be re-created in your course after the import from Commons because of how LTIs are initially set up at the Canvas account level.
All this is to say that you may need to do a bit more investigation on your part...including maybe having a conversation with your school's local Canvas administrator or someone from your school's Online Learning/eLearning department.
I hope this will help a bit. Sing out if you have any other questions...thanks!
