Cluster going down to RED while using synonyms

Hello All...

I am new to elastic search and started implementing it in our project. There is a functionality to use abbreviations search for us and i wanted to make use of synonyms. But after i set synonyms using synonym path, cluster goes to RED. Any one experienced this issue before? Below are my infra and data details. Please note that i haven't changed any default configuration of ES using yml file.

Running ES 2.1 on windows as a windows service
4 GB ram, 300 GB HDD

Two indexes - Locations and LandLots
Location Type- 4 fields, string (building name, postal code, road name, house number)
Land Lot type - 2 fields - string (objectid and lot key)

Before indexing , cluster health is Green
After indexing, cluster heath turns yellow
After applying synonym analyzer settings, cluster health turns RED and all shards goes un allocated.

Q1- Do i need to modify the default settings for ES by updating yml file?
Q2- since i am running ES as a service, how can i view the log file in case of why the cluster is turning RED after applying synonyms?

Any help is appreciated. This is my first post, so if this is a known and solved issue, please redirect me to that.

Thanks,
Sooraj.S

You should check your ES logs to see what is happening.