eM Client doesn't have a valid license

Since upgrading to Windows 10 I am frequently getting the error that I have exceeded my activations.

I have two Pro licenses, each time I am having to deactivate and reactivate both.

This is particularly difficult as I cannot get the Silverlight plug in to work on any of my computers.

Please can you resolve both the erroneous activation exceeded error and provide a non Silverlight license management solution?

Hello, please note that whenever you need to move your license to another computer, you need to deactivate your previous activation license first, to deactivate use the license manager, the plugin can be installed on any of the current browsers, however some latest releases of Chrome can require enabling NPAPI in order to let silverlight work with the browser.

Go to: chrome://flags/ in browser address field to access the settings of chrome to enable it.


Hi Paul

I have enabled the NPAPI setting in Chrome but it still only displays the download Silverlight graphic, same for Internet Explorer and Edge.

I have two licenses on two PCs both of which have recently been upgraded from Windows 8.1 to Windows 10.  I am not moving my license between PCs as they each have their own one.

Frequently when I start eM Client I now get the activation error despite the software having started correctly the previous time.

Really very frustrating and it is making eM Client unusable for me. 

Hello, unfortunately Microsoft Edge does not support Microsoft silverlight anymore but you should be able to run the utility from IE if you have Silverlight installed (it is needed to install the plugin).


Hi Paul

No, I cannot run Silverlight from IE even though it is installed.  Silverlight has been deprecated and final support ends this month so I do not see that I should put great effort into making it work.

This morning was another typical example.

Over the weekend had eM Client working correctly on both of the PCs for which I have purchased licenses.  Shut down the PCs at the end of the day.

Started first PC and got the license error:

Tried to reactivate but got the maximum installations error:

Used an old PC to access the license server, you can clearly see that I have 2 licenses:

Both are activated:

Deleted both of these and then re-activated the first PC:

So there is something that is preventing the license server from recognising that the validation of the license is coming from the correct PC.

Please can you help resolve this?

I am not moving the software between PCs, I have two installations each one of which has it’s own license.



Hello again, I’m not completely sure if I understand, have you been able to re-activate one of your computer, re-activating using your activation key should allow you to use the application features. Unfortunately we have an issue that we were unable to detect before the update has been released in client/server communication.

We’re working on resolving this issue as soon as possible, so far all of our users have reported that re-activating using their license key was a successful resolution of the issue.


Hi Paul

Yes I have been able to re-activate but I am having to do this several times a week.

There is something at start-up that is preventing eM Client from validating it’s license configuration despite it being correctly licensed and activated.

I have just been informed by one of our developers that an old server update was pushed so the issue should be resolved. However the main problem was with trial licenses, if you’re being unsigned of your license periodically it’s possible you’re experiencing a completely different issue.

Please send me your Update URL and HWGUID which you can get by navigating to the about page in Help > About and pressing Ctrl+U (for displaying Update URL) and Ctrl+H (For HWGUID).


Thank you for submitting the details, we believe we have been able to detect the issue, but if the issue reoccurs, please submit the Update URL and HWGUID information to my work mail, [email protected] with a reference link to this forum topic.


Will do, thanks Paul.

Hello, are you able to access the licensing server at http://licensing.emclient.com/service.asmx or are you having issues accessing this web page?


Me too, I have to enter my activation code each time I open eM Client.
Yes, I can access the licencing server.

If this is for a Pro License, make sure that you have not exceeded the number of installations that your license is valid for. If you have 2 licenses, activating it on 3 computers will cause this issue. Or if you have installed it on a new computer, but not deactivated it on the old one, you may get the same problem.

Go into the license manager, and deactivate all activations, then try again. If that does not help, open a support ticket, and eM Client will be happy to assist you further.

If this is for a Free License, you will need to deactivate it on the previous computer before activating it on the new one. A Free License is only valid for one computer. If you do not have access to the previous computer to deactivate it, or want to install eM Client on two computers, then you will need to register a second Free License using another email address.

where is the “License manager” ?

The License Manager is in the support section of the web site. https://licensemanager.emclient.com/