Clone Project - rate types and task types will not be copied

When cloning a project you may encounter one of the following messages

• Rate types and task types will not be copied, because one or more rate types or task types on the source project are not allowed for the engagement type of the new engagement.
• Rate types and task types will not be copied, because one or more rate rate or task types are not allowed for this engagement

This error message isn't particularly useful because of the wording. What it is really saying is that the source project has an inactive entity that cannot be copied. It will either be a

• Standard Task Type
• Standard Rate Type
• Task Type

When you get this message you'll find that the ability to clone rates is disabled. There isn't really a logical explanation to this block other than the fact that rate types, task types, and rate cards are all tied together in the back end.