The cause of this problem will be usually be iOS's Privacy settings. Sometimes, especially during app or iOS updates, it seems that these settings can randomly "reset" in the background so it's always worth checking these first.
To access these settings, please do the following:
1) Access your device's Settings.
2) Tap on "Privacy & Security".
3) Tap on "Photos"
4) Tap on "Site Audit Pro".
5) Tap on "All Photos". (If "All Photos" is already selected, select "None", then go back to the previous screen. From there, tap "Site Audit Pro" again to and then tap on "All Photos" - this will refresh the setting.)
If this doesn't work, please let us know via support@veamstudios.com.