From Forum Nokia Wiki

The SDK comes with a built-in emulator, which is used for enabling the computer to emulate an S60 device. The emulator can be launched from the command line by typing epoc. You will have to set locale information the first time you run the emulator. The sections below provide solutions to some common errors when using the emulator.

The application cannot be started from the emulator menu

If the application shows in the menu of the emulator but cannot be executed even though there is no error messages, something might be wrong with UIDs. Check that the UID for the application is the same in the source code as in the .mmp file.

// "myapplication.hrh"
 
#define _UID3 0xE6642FDE
 
------------
 
// "myapplication.cpp"
 
const TUid KUidMyApp = { _UID3 };
 
TUid CMyApplication::AppDllUid() const
{
  // Return the UID for the application
  return KUidMyApp;
}
 
------------
 
// "application.mmp"
 
UID  0x0 0xE6642FDE

"Cannot start Ecmt Manager"

The emulator provides various tools that assist you. These tools can be accessed by starting the emulator and selecting Tools from the menu bar. To use the tools, you need a working Java configuration on your machine. If you receive an error “Cannot start Ecmt Manager” (see figure below) when trying to use the tools, your version of Java cannot be found from epoc’s configuration file.

Open the file, which is located in “C:\Symbian\9.2\S60_3rd_FP1\Epoc32\tools\ecmt\config\config.properties” by default, and add your current version of Java Runtime Edition (JRE) to the parameter epdt.java.version.start. For example:

epdt.java.version.start=1.4.1,1.4.2,1.5,5.0,1.6,6.0

In the previous line, JRE 6.0 is made available by adding “1.6,6.0” to the parameter.

"ERROR: EPOCROOT must specify an existing directory"

You tried to launch epoc emulator from a network drive. Launch epoc from drive C.