A 'Something Went Wrong' dialogue box appears when a control is added or configured in a Nintex Form. You may find that this issue is only occurring on one SharePoint Site, and other sites may be working as expected.

Navigate to Site Settings > Site Administration > Regional Settings and check that the setting is correct for Time Zone. If issues persist, please try making this setting on the affected site match the setting on a working site.

ULS Logs: Failed to register controls for JavaScript. Error: Specified argument was out of the range of valid values. Parameter name: The name '0' was not found.. Stack trace: at Nintex.Forms.SharePoint.Administration.NFTimeZoneCollection.GetById(Int32 id) at Nintex.Forms.SharePoint.PropertyEditors.TimeZoneToLivePropertyEditor.GetCurrentUserTimeZone() at Nintex.Forms.SharePoint.PropertyEditors.TimeZoneToLivePropertyEditor.HandleControlPropertyDesignerPageLoad(Page page) at Nintex.Forms.SharePoint.NfsUtilities.RegisterControlsForJs(Page page, Control[] controls, String datePickerScript)