Application Errors

Scenario:

A student is trying to open an activity and gets a blank screen or text that reads "Application error: a client-side exception has occurred."

First, check if this is happening for many students or just one student. If it's just one student, please take a screenshot of the error (including the web browser address bar) and contact support. If it's happening for many students, please go to step 2.
Is this happening with all the activities in a lesson or just for one specific activity? If it's all activities, please contact support and let us know! If it's happening with only one activity, please go to step 3.
Are you using a lesson on the Organization Lessons tab or the Lessons You Made tab? If it's an organization lesson, please contact support and tell us which activity is having the issue and the title of the lesson. If it's under Lessons You Made, please go to step 4.
Open the lesson you made or modified and note down the title of the activity that's having the issue.
Next, click the to edit that activity. A panel will slide from the right side asking you to search by topic.
Search for the activity using the title you noted down.
When you find the activity title, click the relevant radio button and then press the Edit button in the bottom-right of the screen.
Once you press Edit, the side panel should disappear. Now press the Save Lesson button.
If you want to check to make sure it's fixed, you can Preview the lesson and run the activity you just edited.

Mission accomplished!