Cisco 7960 error "protocol application invalid"

I am getting " protocol application invalid " error on Cisco 7960. When i switch on unit it says "configuring vlan, then it goes to "configuring IP," after that i got "protocol application invalid." Can some one provide me solution for this ?

Thanks

This error message means that the application image cannot be loaded into Flash memory or that the image does not exist in Flash memory.

Reset your phone factory settings.

Go to the main Date/Time screen then Press **# to unlock Network Configuration on the phone click on settings check that the Network Configuration lock symbol should be unlocked. If it is not, exit to the main screen and press ** # again. then scroll down for network Configuration then Erase Configuration. after completing that press softkey Yes and then save.