Service new sample128

Hi Dialog Team,

I followed AN-B-029 document and was successful in adding new characteristic(notify/read) to my service. However, when i am adding a new characteristic(write/read), i am unable to write in it. Everytime it is showing "Writing to characteristic failed" when i am writing anything.Is there any document like AN-B-029 which will provide the steps? I am stuck in this.

However, now I want to add new services to the existing sample128. And my new service should contain the two characteristics. How should i implement it?Please help.