My project in VSTS got some users. For a particular user X i assigned admin access and on his login, Code menu doesn't appear.
On checking settings -> Version Control, it says
As a stakeholder you can access the backlog, task and kanban boards, work items and manage approvals for releases.
How to migrate an user from stakeholder access to Basic access?
User is not able to access code even from Visual Studio also.
Perhaps, there are no seats available with Basic access (you have only 5 free by default) and in this case, VSTS assigns Stakeholder access. See this article for more details.
VSTS provides with 5 Basic user access, unlimited Visual studio subscriber access and all other's get restricted to Stakeholder access [No access to code]. Find the access comparison here
In case if you need to provide Basic user access, you need to remove/modify basic access of an user to stakeholder and assign the required user with Basic access. Only Account collection administrator could do this.
Steps and Screenshots to change access from Neha Gupta to Shalem Raju are provided below: