FAILED with error "TechnicalError"

During forward testing I received the error listed below:

log tab

06/01/2016 20:00:07.730 | Executing Market Order to Sell 104000 EURUSD (MR: 0)
06/01/2016 20:00:08.199 | → Executing Market Order to Sell 104000 EURUSD (MR: 0) FAILED with error "TechnicalError"

journal tab

06/01/2016 20:00:07.746 | Request to Sell € 104k EURUSD (Price: 1.07517, MR: 0) is sent to server
06/01/2016 20:00:07.792 | → Request to Sell € 104k EURUSD (Price: 1.07517, MR: 0) is ACCEPTED, order OID16450003 created (06/01/2016 19:00:07.770 UTC+0)
06/01/2016 20:00:08.199 | → Order OID16450003 is REJECTED with error ""

I use TradeResult.Error.Value for error logging but is only providing the message "TechnicalError"

TradeResult trrMarO = ExecuteMarketOrder ...
...
if (!trrMarO.IsSuccessful){
Print("Sell not successful. Error:{0}", trrMarO.Error.Value);
}

Is there somehow a way to determine what this "TechnicalError" - or reason of rejection was?

Thanks in advance.