Sanity Check No Error But Unable to Apply Configurations

[nagiostest]

Running /usr/local/nagios/bin/nagios -v /usr/local/nagios/etc/nagios.cfg
Does not give any error. The output is Things look okay - No serious problems were detected during the pre-flight check
However when i try to do some configurations thru the xi interface, the configuration verification fails.
Configuration submitted for processing...
Waiting for configuration verification.......
Configuration verification failed.
Nagios is till able to monitor my services and hosts but i cant do any changes to the configuration using xi interface.
I took a look at the configuration Snapshots and saw that there was 40 over errors. I am very puzzled as to why it doesn't show when i run the sanity check (plus it is able to monitor those hosts that produced the error). Another thing to note : i am able to restart nagios. - doesn't this prove that there isnt any error ? thus it could restart normally?

[scottwilkerson]

this doesn't show in the sanity check, because after you get the failure, XI automatically restored the configuration to the last known good one. and it is that which is used in the sanity check.

From the web UI you can go to Configure -> CCM -> Tools -> Write config files

Work from the top down, fixing errors along the way and ONLY select restart nagios option once there are no errors