User approves a PTO request and chooses to create a time entry for it, but gets an error:
You do not have security permission to access this feature.
This can happen if your security profile restricts you from accessing the time entries of the PTO Project set in Global Settings > Time & Expenses. For example, if you have Manager Level Access security, you can access the time entries of only those projects by default for which you are the manager. If you are not the manager for the PTO Project, you cannot create time entries via PTO approval for it. If you think you should be able to create the entries via PTO approval, you should ask your Core administrator to revisit your security permissions and provide you a higher level security access. Check the Core Help for more on Security.
The option in your security profile that controls whether you are able to access time entries of other projects is Allow access only to entries of projects I manage under Time Entry. If your Core administrator un-checks this option for you, you can create time entries for all projects (including the PTO Project). Check the Core Help for more on customizing security permissions.