You have to use a custom AV pair on TACACS server under user setup to make it work. ACE uses RBAC (role based Access Control) and for that you have to pass the context and User Role from Tacacs server to ACE to make it work.If there is no RBAC info is pushed from Tacacs server and user just get authenticated then the default role assigned by ACE is Network-Monitor.
Following steps (On tacacs server) will make it work
1. Select your user
2. goto tacas+ settings
3. Select " shell (exec)" checkbox
4. Select "custom attributes" checkbox
5. Type your context and role information in custom attrib box, using following format
shell:*
for e.g (if context name is Admin, domain is default-domain and you want to assign role "Admin" to this user )
shell:Admin*Admin default-domain
Hope it helps
Syed