Issues starting the EMS


Two of us doing this course have got stuck (independently) on exactly the same place in the course. In the Connectivity to IOT (basically around M3:17 onward) we are unable to start the EMS successfully. I have spent 3 hours on my own and 1 hour with the other person trying to figure this our, so far without success and need guidance. It’s probably staring me in the face.

We have downloaded the certificates as indicated, and created the keys as indicated on a few occasions. Extract from last attempt with logging set to DEBUG.


I am having the same issue. Any help would be great!


If anyone is running in to this Issue. I ended up getting around it by using the “q” command to stop the EMS. going in to the “/microserver/etc” directory and deleting the “config.json.booted” file and then starting the EMS from a command prompt again. I seemed as though the EMS was defaulting to use the “last known good configuration” if you did a “crtl+c” to close the process.
Additionally I noticed that the EMS would start and respond to commands but would not have a prompt. So after you have started the EMS, it looks like it hangs after a series of 3 errors (TlsStream, HttpClient, emsRequestHandler). However, it will respond to commands and I was able to see my bound device using the “l” command and accomplish the file transfer.
YMMV just my experience.


Hello! If you are running into this issue and you are in Milestone 3, the errors are expected. They occur because your EMS is trying to connect with a process manager to find out what properties and services the remote thing has. At this point in the course, you do not have a process manager yet, so the EMS returns those errors. In other words, if you get those errors is because you are missing a process manager. You can get more information of you go to milestone 3, activity 22.


I’m having an issue on this module as well, however it’s not the same issue as the original poster. The issue appears to be certificate related. In the training it walks you through steps to fetch a certificate which I was able to follow however the EMS is saying this certificate is invalid, I’ve tried all three certs from the certificate tree and they all produce the same invalid certificate error. Here is the screencap, the bottom lines repeat until the window is closed.

I was able to get around this issue by adding a logger to the JSON, not sure why this parameter has an impact on the EMS connecting successfully or not but here is my JSON contents, the only difference between the failure I showed above and the successful connection is the addition of this logger. In this example certifications validate is set to false, this setting still would fail to connect.

“ws_servers”: [{
“host”: “”,
“port”: 443
“certificates”: {
“validate”: false

"logger":	{
	"flush_chunk_size": 16384,
	"buffer_size" : 4096