The user can receive a task for approval but can not receive email notifications. No errors appear in K2 Workspace.
The following error was found in the EventBus.ClientRecorderError table in the K2 database:
"System.Messaging.MessageQueueException (0x80004005): Insufficient resources to perform operation."
The error message indicates that the messages that K2 is trying to send is hitting the size limit imposed by MSMQ (4MB):
Thus client event notifications won't be sent with attachments of 3MB or more.
This is a Microsoft limitation. To workaround this issue:
1. Send attachments in the Email Event instead.
2. Add a link in the notifications for your users to access the attachments in your server, instead of attaching the files to the notification.