I'm having the same issue. I had a heck of a time getting the router to accept a lease from the cable company modem and when it finally worked I couldn't browse the web. Tried an nslookup from a client and the DNS server in the router wasn't responding, tried to log into the web interface for the router and got the "/etc/config/luci seems to be corrupt" message.
/usr/lib/lua/luci/dispatcher.lua:211: /etc/config/luci seems to be corrupt, unable to find section 'main'
stack traceback:
[C]: in function 'assert'
/usr/lib/lua/luci/dispatcher.lua:211: in function 'dispatch'
/usr/lib/lua/luci/dispatcher.lua:195: in function </usr/lib/lua/luci/dispatcher.lua:194>