We recently started experiencing an error with converting leads and editing accounts, which I suspect was caused by inactivating a user who is no longer with our company (since this is the only change we have made in the period before this problem started last week). When a user (any user, even an admin) attempts to convert a lead or make an edit they receive:

Error: System.DmlException: Insert failed. First exception on row 0; first error: CANNOT_INSERT_UPDATE_ACTIVATE_ENTITY, GenerateNewOrder: execution of AfterInsert caused by: System.QueryException: List has no rows for assignment to SObject Trigger.GenerateNewOrder: line 6, column 1: [] (System Code)


After contacting Salesforce Support they suggested that there was an issue with a trigger that was causing the error we were receiving since the trigger was referencing a user who no longer existed. However, I miffed as to WHICH trigger it may be since we have dozens set up. Salesforce support has suggested the following which is essentially Greek to me and I am not quite sure where to start:

1. Check the Debug logs and get to the line number of the class where it's throwing that error message.

You will get a query on that line number.

Run that query in the developer console and you should get zero records.

This error occurs when query doesn't return any rows. For e.g.

Account a = [select id, name from Account where name = 'test'];

To avoid this exception, create a list of account

List<Account> lstAccount = [select id, name from Account where name = 'test'];
if (lstAccount.size() > 0)
{
Account a = lstAccount.get(0);
}

2. Alternatively, you now know the exception, so you can use try/catch as well.


Any suggestions? I'm really unsure where to start by even narrowing down which trigger it should be, just short of going through each and every one...