EFII "Error Reading Scenario File"??

[Rupert]

Hoping someone may know the cause and fix for the "Error Reading Scenario File" problem I'm currently facing.

Using EFII GOLD, I have encountered this error when trying to start the following scenarios.

1) Last Tank Battle.
2) Duna Ridge.
3) Impending Doom.

In the case of 1 & 2, scenario loaded after the error but no map or units.

With 3, again scenario loaded after the error, this time the map did appear but alas no units.

Is this a map conversion or expansion disk issue?

Thanks in advance.
Thomas