Some staff may experience an issue where, every time they try to click on anything or perform a function in CRM, a new window is opened with an error. However, if they close the error box and the window, they can continue working.
This is usually caused by an option to Opt In to Learning Path. To resolve this, click on the cog up the top-right of the screen, then select Opt Out of Learning Path. Once the page reloads, the issue should no longer occur.