When setting up Perusall as an LTI app, make sure that your LMS is sending name, email, and role information to Perusall; Perusall uses this information to assign users the correct role (student or instructor) in the course, show student names in conversations, and send students email notifications when other students respond to their questions or comments. (For example, Canvas has a "Privacy" dropdown that should be set to "Name only" or "Public.")
If LTI launch fails, ensure that your LMS is sending all of these required fields (in particular, some LMSs do not send
tool_consumer_instance_guid by default, and some fields will not be sent without the proper privacy settings from above):
tool_consumer_instance_guid(an ID number uniquely identifying your LMS)
user_id(an ID number uniquely identifying each user)
roles(LTI standard role identifier)
resource_link_title(placement identifier, if gradebook sync enabled)
lis_outcome_service_url(URL to post grades back to, if gradebook sync enabled)
lis_result_sourcedid(indicator of grade passback location, if gradebook sync enabled)
Make sure that you have selected the option to open Perusall in a new tab or window; otherwise, LTI launch will fail. Perusall blocks LTI launches within an iframe for security reasons.
Perusall uses the email address as a unique identifier for each user. If a user already has a Perusall account under the email address on file with the LMS, then LTI launch will fail with the messsage:
There is already an account with the email address [user's email address] so we can't create a new account using the same address.
To resolve this, the user should log in to their existing Perusall account and change the email address in their profile to something different. (To edit a profile, click your name/initials/photo in the upper right corner of the page, and then select "Edit profile.")
Alternatively, Perusall Support can disable an existing Perusall account for users in this situation.
Some LMSs fail to properly process LTI launches when the assignment description for an assignment that launches Perusall contains newline characters. Place the description of the assignment on one line.