'Access denied' to Content Type
From the limited details provided in your question, it could very well be that one of your enabled rules (created with the Rules module) is what is causing your issue.

To actually confirm, for sure, if it is any of the enabled rules, use these steps:


Disable of all your enabled rules. If the problem persists, you can be sure it is not because of a custom rule (don't forget to re-enabe the temporary disabled rules). If the problem is gone, continue with the next step to find which rule is causing your problem.
Re-enable your temporary disabled rules, but only 1 at a time, and check if your problem comes back (each time after you re-enabled one more rule). At some point your problem should come back. As soon as that happens, the most recent re-enabled rule is what is causing your issue. In that case, re-enabe the remaining temporary disabled rules and continue with the next step.
If you cannot find out what the actual problem might be in the re-enabled rule that causes the problem, move on to Rules debugging, as explained in my answer to "How can I display the value of a variable inside a condition?".


After you're sure it's not Rules causing the problem, I'd consider the "Workflow" module (which you also seem to be using) as the next suspect on my list. As a quick test (to see if that's the direction to go for further debugging), temporary disable the Workflow module: if the problem remains, then it is not the Workflow module either (don't forget to re-enable it afterwrds).