When i am submitting the record for the first time getting an error " Invalid insert"

[subbarayudu]

When i am submitting the record for the first time getting an error " Invalid insert"  and when we click the second time we can see a registration email being sent.

what was the reason for error and how to debug  and Could you please let me how to solve it
Thanks in advance
 

[Mark Manders]

Can you check the system log? Does it state anything about this record? There can be a number of things stating it's an invalid insert (and it can even be another record is being inserted that fails for some reason). Check business rules/flows that are triggered by an insert of the record.