VTP -Password Error and Solution
When using a VTP password to enable membership in the VTP domain, make sure that the password is set correctly on all switches in the VTP domain. If a password is used, it must be configured on each switch in the domain. Cisco switches do not use a VTP password by default.
How to configure VTP Password
SW2(config)#vtp password cisco
* Verify that passwords are all the same on all VTP enabled switches in the VTP domain