When users are setup in Web TimeSheet, it is mandatory to assign them the correct seat assignment and provide them appropriate permission, under the Access tab of their user profile.
If users have access to all the modules of Web TimeSheet, but no permission assigned to their profile, then they will not be able to access any of the eligible modules.

Seat assignment control the modules / product licenses that users are eligible to access, where as Permissions control the accessibility within these eligible modules.

Note:
You will need administrative rights in Web TimeSheet to access a Users profile and make the necessary changes.