When you integrate Perusall with your Learning Management System, certain content will not load properly if your LMS launches Perusall within a frame, rather than in a new tab/window. (Launching Perusall within a frame also does not provide the optimal student experience, since the interface components of the LMS take away screen real estate from the content.)
Edit the assignment settings, and under Submission Type check the box Load This Tool In A New Tab:
Web Links added to the left-hand navigation menu or within a Learning Module cannot be opened within a new tab/window, so make sure any Perusall links are created within a regular content area. Edit the Web Link and change Open In New Window to Yes:
Navigate to Site administration > Plugins > External Tool > Manage Tools, and click the gear button to edit the Perusall tool. Then change Default Launch Container to New window under the Tool settings area:
Click the down arrow next to the Perusall link you have created in a content area, and then click Edit Properties In-place. Then check the Open as External Resource box, and reload the page.