Access denied when creating TFS Release definition

I'm trying to setup a release definition on TFS but I'm running into an access denied message:

I thought I should have this permission, since I am part of the "Agent Pool Administrator" group:

I noticed however, that my queue has no roles, and that I can't add one for some reason, which I suspect to be the related to the problem:

My question is how do I correctly configure the permissions? I've already googled a bunch but I still couldn't pinpoint what exact permission I'm missing.

[[Update]]

This is TFS 2015 update 3

Apparently, I am myself a project collection administrator already, but still don't have queue permissions and don't know, or can't see where to add myself as a queue admin.

The said queue was created by me, but indirectly, I created the agent pool with the auto-provision queues checked, and that created the queue, however, if I try to directly create a queue, I run into another "Access Denied" error

[Update]

Trying to run tfssecurity /collection:http://wada-pc:8080/tfs/DefaultCollection /g+ "[Agent Queues]\Agent Queue Administrators" "domain\account"

Leads me into Error: Access Denied: Eduardo Wada needs the following permission(s) to perform this action: Edit collection-level information

However, I should have that permisison:

Yes, your issue is related to the agent queue roles. An agent queue provides access to a pool of agents. Usually, there are two groups under the Roles:

Agent Queue Administrators: People in this group can register new agents in that pool, add users to the Agent Pool Service Accounts and add other administrators to the pool.

Agent Queue Users: For Team Foundation Server the service account you specify for the agent (commonly Network Service) is automatically added when you register the agent.