Refer to the exhibit.
R1(config)# router bgp 100
R1(config-router)# neighbor 10.110.110.2 remote-as 200
R1(config-router)# neighbor 10.110.110.2 password Cisco
R1(config-router)# network 10.100.100.0 mask 255.255.255.0
R2(config)# router bgp 200
R2(config-router)# neighbor 10.110.110.1 remote-as 100
R2(config-router)# neighbor 10.110.110.1 password cisco
R2(config-router)# network 10.200.200.0 mask 255.255.255.0
A network engineer manually reconfigures the BGP configuration on newly upgraded router R1. However, the BGP neighbor relationship does not come up with the directly connected neighbor router. What is causing the failure of the BGP neighbor relationship between routers R1 and R2?