Only one of my three classes gives the message "Your LTI tool has been misconfigured, please contact your institution's Canvas Admin"
I was told to ask here for help.
Your canvas admin will have information more specific to the external tool that is giving you this error. You will need to know the specific tool and the action that produces the error. If your canvas admin cannot help, you might want to ask canvas support. https://community.canvaslms.com/t5/Canvas-Basics-Guide/How-do-I-contact-Canvas-Support/ta-p/389767
If you do not know which tool is causing the problem, you can try going to course settings > navigation and move any tab that your course does not use to the bottom half of the list. Then click save at the bottom of the page. This will remove from the navigation options any external tool you do not need. To see the complete list of eternal tools installed in this course, go to Settings > apps and select "installed"