Known Issues in Canvas

This page includes ongoing issues that have been reported to the Penn community. For a full list of all known Canvas issues, visit Canvas Community Known Issues.

Click on a link to view Canvas known issues:

Browser Issues

Mime Type Issue in Firefox

There is Firefox-specific bug that can affect mime types for files. Older versions of Firefox can sometimes produce a mime-type error when uploading files to a website. When this happens for files uploaded to Canvas, the file does not render correctly in the Canvas previewer because the browser interprets it as another file type; consequently, users either see  a string of code in the previewer or do not see the magnifying-glass icon for previewing the file at all. Fortunately, this bug does not affect users’ ability to download files, just the ability to preview them, so anyone with access to a file in a Canvas site can download it by clicking on the file link even when the file preview is not working.

To fix this issue, you can do the following:

1. Check to see that you are using a supported browser version. Whether you are using Firefox or another type of browser, please note that you should always use a version of a browser that Canvas supports to avoid issues affecting older versions. Please consult this list to see the browser versions Canvas currently supports. 

If you are already using a supported browser version, please clear your browser’s cache. Here are instructions for how to clear a cache on a PC.

And here are instructions for how to clear a cache on a Mac.

Then, please close the browser.

2. Open the browser and log into Canvas at with your PennKey username and password. Then, drag your mouse over the Courses tab and select the course containing the affected file.

3. Click on Files and then delete the file presenting issue by following these instructions.

4. Upload the file again by following these instructions.

After you save the changes, please check to see if the file previews correctly. If it does not, please email us at so we can investigate further.

Lost SpeedGrader Comments in Firefox

We have learned about a new Firefox bug affecting SpeedGrader. When a Teacher, TA, or Grader uses the margin commenting feature for annotations in SpeedGrader with Firefox, they must click outside of the comment bubble on another area of the document in order for the comment to be saved. This has led to several cases where final comments are not being saved when the user navigates to the next student submission.

We recommend the following workaround for this issue:

  • Use a supported version of Google Chrome or Safari instead of Firefox.
  • If you must use Firefox with SpeedGrader, make sure to click out of the comment bubble onto another area of the screen when adding your final comment on a paper to ensure that it is being saved before navigating to the next student submission.

Also, please note that if you leave SpeedGrader open for a submission for a long time, you can also lose comments, even when working in supported browsers.

Browser Extensions and Third-Party Tools

There have been several issues in recent months that were remedied by turning off all browser extensions and by checking if any Third Party tools were running.

Regardless of browser, please turn off any extensions you may be using if you are having difficulties accessing Canvas or Canvas-integrated tools.

Notifications, Announcements, and Emails

No Email Notifications for Courses in Future Terms, Just Push Notifications

Users do not receive email notifications for actions taken in courses in future terms. For example, if you are a student in a course that is set up in Canvas for Fall 2022, and it is currently Summer 2022, you will not receive email notifications if your instructor takes an action (e.g., creates an assignment). This issue occurs even for courses that are currently active but are technically associated with a future term (e.g., a Fall 2022 course that actually starts in Summer 2022). Users do receive push notifications for these type of actions, however. To learn more about push notifications, please see “Set Push Notifications” on this page (instructor information and student information).

Not Receiving Email Notifications? You Might Need to Confirm Your Email Address

Users who have not confirmed their email addresses in Canvas do not receive email notifications. If you notice that you are not receiving email notifications, please check to see if your email address is confirmed by clicking on Account > Settings in the upper left corner of Canvas.

Announcements Index in Course Navigation Menu Intermittently Stays Hidden When an Announcement is Added

Sometimes, the announcements tab in the course navigation menu may intermittently stay hidden after the first announcement is added to the course rather than becoming visible as expected.

Updating the course settings in any way should cause the Announcements tab to become visible.

Grading and Quizzes

Timeout Issues in SpeedGrader

SpeedGrader has a session timeout of 10 hours. Canvas will display a session expiration warning at 9 hours 50 minutes, followed by a 5-minute and 1-minute warning until the 10-hour limit has been reached.

You can restart a DocViewer session at any time by refreshing the submission page.

Grading History Not Displaying All Grade Changes

The Canvas grading history for a student’s assignment grade only shows the two most recent grade changes in the last 24-hour period. Any additional changes made in this period are not saved.

No Quiz Statistics for Classic Quizzes with More than 100 Questions or 1,000 Attempts

Quiz statistics aren’t available for Classic Quizzes with more than 100 questions or 1,000 attempts (i.e., more than 1,000 quiz submissions from students for a single quiz). When you click on the Quiz Statistics link for a quiz that exceeds these maximum values for questions or attempts, the following message appears:

Cartoon panda crying and the message,

Please consult the “Canvas Quiz Item Analysis” document for more information on the benefits and limitations of Canvas quiz statistics.

Item analysis may not generate results within specific quizzes. Here are a few limitations to consider within analysis reports.

  • Currently, analysis is designed to work with quizzes that deliver the same questions to all students. Therefore, if you generate the item analysis CSV for quizzes that pull from a question group, the CSV will generate a line representing each version of the quiz.
  • The Quiz Item Analysis report currently only supports Multiple Choice and True/False quiz questions.
  • If a quiz allows multiple attempts, the calculations will only consider the student’s first attempt (to rule out practice effects).
  • Questions that are left blank or not answered count as wrong when determining the total score for the exam, but they are excluded from question-level calculations.
  • Statistics only include data for students who attempted to take the quiz.

As a workaround, you can view quiz statistics by downloading the CSV files in the Student Analysis and Item Analysis links. You can then upload the file to Excel, Google Sheets, or another spreadsheet and view the data in a much more user-friendly format.

Gradebook-Export Name-Sorting Issue

When you export the Canvas gradebook, sort the export by any column other than the “Student” column (for example: the “Final Score” column), and the re-sort the export by the “Student” column, the second sort re-orders the rows alphabetically by students’ first names instead of by their last names. When a gradebook is exported, the file is sorted alphabetically by last name, so a re-sort of the “Student” column after another column has been sorted does not restore the file to the original sorting order. Our vendor is currently working on a solution for this issue. An update will be posted to this “Known Issues” entry when a solution has been implemented.

Post Final Grades for Muted Moderated Assignments before Unmuting

If a moderated assignment has been unmuted before a moderator posts final grades for the assignment, Canvas generates a notification that the assignment has been unmuted, but the grades and feedback on the assignment are still unavailable to students because the final grades have not be posted. For this reason, it is recommended that final grades for muted moderated assignments be posted before they are unmuted so that the notifications students receive about the assignment being unmuted will accurately reflect the availability of the assignment’s grades and feedback.

Managing Files

“Export Failure” for Duplicate File Names

When a Canvas site contains files with the same name, an “export failure” occurs for course content exports. To fix this issue, a Teacher, TA, or Designer will need to delete duplicate files, or, for different files with the same name, they will need to rename all files except one.

Downloading .csv Files From Canvas

Safari users will need to change a privacy setting in their web browser to download a .csv file from Canvas. If the setting is not changed, the default format, after downloading, will be .txt.

To correct this, in Safari’s Preferences:

  • Choose Privacy
  • Website tracking
  • Uncheck “Prevent cross-site tracking”

General Issues

Video Comment in Peer Review Marked “Incomplete”

Video comments submitted for a peer review are marked “incomplete” if they don’t have accompanying text. To avoid this issue, students should add text to their video-comment submission for peer reviews (e.g., “This is my submission”).

“Session Expired” Message When Viewing a Public Canvas Site

A “session expired” message and a log-in prompt appear after several minutes of viewing the public version of a Canvas site either for users whose login data has been saved in Canvas from a prior session or for users who are logged into Canvas in another browser window.

There are two possible solutions for this issue:

1. Log out of Canvas and clear your browser’s cache before accessing the public version of a Canvas site. Here are instructions for how to clear your browser’s cache:

Clearing your cache on a PC

Clearing your cache on a Mac

2. Use Google Chrome’s “Incognito” mode if you want to remain logged into Canvas while viewing the public version of a Canvas site (more information on Google Chrome’s “Incognito” mode).

Since this issue only affects users who have access to a Canvas instance, anyone outside the University of Pennsylvania who is not associated with a Canvas instance should not experience this issue. If a public version of a Canvas site is accessed by someone at another institution that has a Canvas instance, they should follow either of the above suggestions to avoid seeing the time-out message and log-in prompt.

50-User Limit for Collaborations

A maximum of 50 users can be added to a Collaborations Google Doc in Canvas. If there are more than 50 users enrolled in the course site, the Collaborations tool will display only the first 50 users alphabetically.

Hanging Indentations in DocViewer

There is an extra carriage return to the formatting for hanging indentations for documents displayed in the DocViewer that use unsupported fonts. This misformatting only affects how a document displays in the DocViwer and does not affect the file itself; when downloaded, the file displays the correct formatting. Our vendor is working on a fix for this issue, and an update will be posted to this “Known Issues” entry when it is resolved.

Limited Functionality in SpeedGrader’s DocViewer

As of April 2023, users have reported the need to download .pdf or .docx submissions to view or annotate student work, and some have reported the inability to select text using the “Selector” tool as if to copy/paste.

To fix this issue, update your browser to the latest version and clear your browser’s cache. If using Safari, make sure to update Safari to the latest version first then, if the issue persists, uncheck “prevent cross-site tracking” in Safari’s Preferences under “Privacy.”

For the issue specific to the inability to use the “Selector” tool for copy/paste purposes, consider downloading each student’s submission from SpeedGrader and copy/pasting from Office 365 or Word.

    Points Display for Ungraded Surveys in Modules

    Users have reported experiencing an intermittent issue affecting ungraded surveys added to modules. When this issue occurs, a point-value (e.g., “1 pts”) displays in the module listing for an ungraded survey that has been added to a module. Our vendor has confirmed that this issue only affects how ungraded surveys display in modules and has verified that ungraded surveys that this issue affects do not count toward the total course grade. Our vendor’s engineers are working on a resolution for this issue, and an update will be posted to this “Known Issues” entry when the issue is resolved.

    Some Special Characters Count as Words in the Rich Content Editor

    These symbols each count as a word in Canvas’s Rich Content Editor:

    `  ~ $ ^ = + > <

    If you are an instructor or TA, it is recommended that you take this restriction into consideration if you are asking students to follow a word-count limit. If students will need to use these symbols, please factor the approximately number of instances a student might need to use these symbols for the following types of activities:

    • Text-entry assignment submissions
    • Discussion posts
    • Essay questions for Canvas quizzes
    • Pages that students can edit

    If you are a student, please take this restriction into consideration if you have been given a word-count limit for:

    • Text-entry assignment submissions
    • Discussion posts
    • Essay questions for Canvas quizzes
    • Pages that students can edit

    Last Updated: 7 Apr 2023