Post NBI subnet get an error,this feature is good last days

From Jenkins:
Case 5: Virtual Network NBI Test - Subnet - FAIL Test Subnet Post NBI Verify Stored Data is same with Post Data
5.1 Generate Post Data - No Result
5.2 Post Network Data via HTTP(Post Subnet need post network) - PASS
5.3 Post Subnet Data via HTTP - FAIL
Post Subnet Failed 500,java.lang.IllegalArgumentException: Class is not registered: org.onosproject.vtnrsc.DefaultSubnet
Note: To register this class use: kryo.register(org.onosproject.vtnrsc.DefaultSubnet.class);
5.4 Get Subnet Data via HTTP - PASS
5.5 Compare Post Subnet Data via HTTP - PASS