Fix schema

Which version are you using? Photoswipe 5.x or 4.x? Have you run "drush updb" after upgrade to 5.x? These configs shouldn't exist anymore and they should have been cleared through photoswipe_update_9003.

@Grevil: We're using 5.0.0.
Thanks, I'll try a manual fix and resave the form to see that happens.

@Grevil: I think I found the reason. Seems the update hook is incorrect:

Most of these options are below "options" key!

langcode: de
photoswipe_always_load_non_admin: false
enable_cdn: false
options:
  showAnimationDuration: 333
  hideAnimationDuration: 333
  zoomAnimationDuration: 333
  maxWidthToAnimate: 4000
  easing: 'cubic-bezier(.4,0,.22,1)'
  bgOpacity: 1.0
  spacing: 0.12
  initialZoomLevel: fit
  secondaryZoomLevel: '2.5'
  maxZoomLevel: '4'
  allowPanToNext: true
  loop: true
  wheelToZoom: false
  pinchToClose: true
  clickToCloseNonZoomable: true
  closeOnVerticalDrag: true
  trapFocus: true
  returnFocus: true
  escKey: true
  arrowKeys: true
  imageClickAction: zoom-or-close
  tapAction: toggle-controls
  doubleTapAction: zoom
  bgClickAction: close
  closeTitle: Schließen
  zoomTitle: Zoom
  arrowPrevTitle: Vorherige
  arrowNextTitle: Weiter
  indexIndicatorSep: ' / '
  errorMsg: 'Das Bild konnte nicht geladen werden.'
  preload:
    - 1
    - 1
  preloaderDelay: 2000
  mainClass: ''
  showHideOpacity: false
  maxSpreadZoom: 2
  closeOnScroll: true
  mouseUsed: false
  history: true
  focus: true
maxZoomLevel: null

And maxZoomLevel was only set to a value, not deleted. It's existing twice in the config.

PS: Of course this can be a local bug, but I don't think so, because I should have noticed a possible error.

To reproduce this, perhaps install a version before that update hook first and then update?
Then you should see the results.

Okay I think it was a local issue. I deleted the old config and resaved the settings, now it looks fine.

Let's close this until someone reports the same.