Fix #1199

app/templates/editor/modal/save-version-modal.jade

@@ -36,6 +36,9 @@ block modal-footer-content
       button.btn.btn-sm#agreement-button(data-i18n="versions.cla_agree") I AGREE
     if view.isPatch
       .alert.alert-info(data-i18n="versions.owner_approve") An owner will need to approve it before your changes will become visible.
+    .save-error-area
+      if view.savingPatchError
+        .alert.alert-danger Unable to save patch: #{view.savingPatchError}
 
   .buttons
     button.btn(data-dismiss="modal", data-i18n="common.cancel") Cancel

app/views/editor/modal/SaveVersionModal.coffee

@@ -46,6 +46,7 @@ module.exports = class SaveVersionModal extends ModalView
     }
 
   submitPatch: ->
+    @savingPatchError = false
     forms.clearFormAlerts @$el
     patch = new Patch()
     patch.set 'delta', @model.getDelta()
@@ -60,8 +61,10 @@ module.exports = class SaveVersionModal extends ModalView
     return unless res
     @enableModalInProgress(@$el)
 
-    res.error =>
+    res.error (jqxhr) =>
       @disableModalInProgress(@$el)
+      @savingPatchError = jqxhr.responseJSON?.message or 'Unknown error.'
+      @renderSelectors '.save-error-area'
 
     res.success =>
       @hide()