Access denied while saving resource

While saving resources, it only shows access denied prompt error message. I'm using modx revolution 2.2.14 . While saving other resources, it works correctly and saves the resource but doesn't work while saving the children resource of a specific resource.

While debugging it shows http://siteurl/connectors/index.php issue with below info:
HTTP_MODAUTH
modx54cb3311eef7b7.00860410_17557160bccaa9673.97947654
action
resource/locks/release
id
718
Source
action=resource%2Flocks%2Frelease&id=718&HTTP_MODAUTH=modx54cb3311eef7b7.00860410_17557160bccaa9673.
97947654

If I'm not wrong (which I often am) this would indicate your particular user group doesn't have the permissions "remove_locks" and/or "steal_locks" selected in your access policy. Can you use the Manage/Remove Locks option from the manager menu, and if so, do you get the same error after doing so?