Your project admin added a precondition called Check Language Definition Association on Files in your process configuration for your RTC project area.  This operation can be found under Team Configuration->Operation Behavior->Deliver(client).  This requires every source member that's being delivered to have an associated Language Definition.  Language definitions are part of the Enterprise Extensions feature of RTC that associates type information with the source member for EE build purposes.  If this is Eclipse project contains source for mainframe or IBM i platforms, this precondition makes sense.  There are options to allow overruling that precondition and exclude certain file extensions from the enforcement.  If that's insufficient, I'd say that that precondition should be removed.