I have the lastest version of MT and I've had this error a few times when I enter a ticker on a chart. Everything seems to be working fine though.
Medved Trader encountered an Error
Object reference not set to an instance of an object.
Please contact Medved Trader technical support and provide the error details
AppVer: 1.1.2052.1321 Err.Flags: Log, ShowIndicator, ShowToUser
at MT.Streamer.Streamer.DoStreamingSubChanges() in C:\MedvedTrader\MT\Streamer\Streamer.cs:line 2889