We have an IPhone 10 that had been working fine with Survey123 ver. 3.0.149 but all of a sudden could not send surveys. No warning messages or anything. Made a backup of the ArcGIS folder from the IPhone to PC and then tried the following in order:
1. Restart Iphone
2. Delete Submitted Surveys
2. Edit and Resend survey from the Outbox
3. Fix database option in Survey123 App
4. Reinitialize Database (cleared all survey data but still couldn't send a new survey)
5. Remove Survey123 and reinstall Survey123 (this finally resolved the problem)
One thing of note was the backup copy of the surveys we made on the PC contained over 1,200 photo attachments in the folder "My Survey Attachments" dating back to June of 2018. I figured photo attachments would be cleared out when submitted surveys are deleted. Could this have been the cause of the application sending issues? Further testing on different surveys and different iphones results in the same issue with the My Survey Attachments. Only way to clear out old photo attachments is to remove and reinstall survey123 app. Is this by design or is their another way to clear out historic attachments?
The files in the My Survey Attachments folder are not are not automatically cleaned when submitting surveys and are kept on the device as a backup in case they are needed again. If using the Sent box or Outbox on the device, these files may be needed to be referenced if copying a survey record for editing to a new one. Uninstalling and reinstalling the app on iOS will remove these files, or via iTunes the folder can be browsed to and the files removed. On Android and Windows the folder can be browsed on the device via a file manager or via USB to a PC, and files deleted when no longer required from that folder.
The number and size of the files in this folder should not impact the ability to send surveys via the app.