TitleGetting Access Denied when creating an item using qListForm by a user with Contributor rights
Try to use native SharePoint web part and see if you're able to add the item.
To use the native web part:
1. Open the page for editing
2. Unhide SharePoint web part
3. Close qListView web part. (it will be placed in the Closed section of web part gallery, so you can re-add it back after closing)
4. Stop editing the page and try adding a new item in the list.