When I try to copy any page on my website I get an invalid HTML entered error and if I edit the page, I get the same error. Why is this happening?
This error can happen when the user editing the page also has the Student role. The Student role disrupts the admin rights of the user. To resolve this, either graduate the user as an Alumni or remove the Student role entirely. This Knowledgebase article goes over how you can remove the Student role - https://kb.blackbaud.com/articles/Article/102609.