Mail Chimp Plugin for 4.60 Error

I just upgraded my store to 4.60.   I'm seeing this in the error log.  I've double checked that the NewsLetterSubscription table does not have a blank email.

MailChimp error. Object reference not set to an instance of an object.

System.NullReferenceException: Object reference not set to an instance of an object.
   at MailChimp.Net.Core.BaseLogic.Hash(String emailAddressOrHash)
   at Nop.Plugin.Misc.MailChimp.Services.MailChimpManager.GetDeleteSubscriptionsOperationsAsync()
   at Nop.Plugin.Misc.MailChimp.Services.MailChimpManager.GetSubscriptionsOperationsAsync()
   at Nop.Plugin.Misc.MailChimp.Services.MailChimpManager.<>c__DisplayClass76_0.<<SynchronizeAsync>b__0>d.MoveNext()
--- End of stack trace from previous location ---
   at Nop.Plugin.Misc.MailChimp.Services.MailChimpManager.HandleRequestAsync[T](Func`1 request)

This has already been discussed in this topic. We cannot reproduce the error. Need more details.

After some trapping, it seems to be in the MailChimpManager.cs unint around 576 where it's calling the Hash method.  There's no check to see if the record.Email is null.   I added the following to help prior to the has call:

                    // Verify not a null email
                    if (record.Email == null)
                        continue;

There's a similar call around line 525 where I did same thing:

                    // Verify not a null email
                    if (subscription.Email == null)
                        continue;

This seemed to resolve the object error.

Thanks for your investigation. We'll add this too.