If there is a % sign in the hint of a question on the Survey123 for ArcGIS website, the survey becomes uneditable and the rest of the website breaks until the page is refreshed.
The Design tab of the survey can be recovered using this workflow via Fiddler.Within the Design tab of the broken survey, when users click the Save button, the applyEdits call is sent. Users can see this within Fiddler.On this applyEdits call, within the Request under WebForms, users see an 'Add' section with the JSON of the survey.Grab all of the JSON in the Add section and paste it into Note Pad ++Do a Find + Replace for all of the % in the JSON, replace them with just an empty space.Then copy this modified JSON. Go back into Fiddler, right-click the applyEdits call > Replay > Reissue and Edit. Paste the modified JSON into the same Add section and click 'Run to Completion'.Check the Response to make sure it says: success: true.When users go back into the survey's design page, there will be some funky looking characters, but they can be removed and now the design page is accessible.