Issues are "disappearing" just after creation

Added by Igor Panassiouk about 5 years ago

Sometimes after issue creation users received e-mail with all issue information but issue itself doesn't exist on the server and issue number is inaccessible. Next issue are creating with next free number

What is the cause may be and is it possible to "restore" missed issues?

Config: Redmine 2.3 on ubuntu, server and database are on different VM's.
Many plugins but before this issue first happened nothing was changed for couple of weeks.