1. What is the difference between Tibco.EMS and Tibco.EMS.UFO 
2. How to use the RecoverConnection() function in DotNet client.

TIBCO.EMS.UFO.dll is a part of the .NET API for Unshared State.mUnshared state connection must be created using an unshared state connection factory

1. What is the difference between Tibco.EMS and Tibco.EMS.UFO ?

TIBCO.EMS.dll is .NET API whereas TIBCO.EMS.UFO.dll is a part of the .NET API for Unshared State.
Unshared state connection must be created using an unshared state connection factory.
Before creating the connection factory, ensure that C# Applications Include the TIBCO.EMS.UFO.dll file.
To create unshared state connections,you can use the relevant methods present in TIBCO.EMS.UFO package.

2. How to use the RecoverConnection() function in DotNet client?

void TIBCO.EMS.UFO.Connection.RecoverConnection  ( )    

Recover the broken connection on another available server. The session, message producer, message consumer, temporary destinations created by this broken connection are transparently recreated once the connection is recovered.

When a client setup for unshared state detects a lost connection to server (A), it attempts to connect to server (B), as defined in the connection factory."Once the connection is detected as broken (On exception listener) you can then call, tibemsUFOConnectionFactory_RecoverConnection in order to recover the connection (This function is used to recover the broken connection on another available server. )

We have sample of a basic csUFOMsgConsumer and csUFOMsgProducer.I have attached it with the case.Kindly refer this in case of your concern.You can refer various sample programs, and These will be found under C:\tibco\ems\<vers>\samples\cs directory.