How to apply the license key?

How to apply the license key?

Scheduler .NET is distributed under Commercial and Enterprise Licenses. Once you buy a license you get the license key (over email) that you need to use to activate the library.

Please, don't mix up the license key with the license number. These are different things.

To activate the scheduler you need the license key. In the confirmation letter the key looks like this:

The key is applied in the app settings of the web.config file as shown below:

        <add key="dhx_license" value="putYourLicenseKeyHere"/>

As the value of the dhx_license key you should specify your license key.


  • If the dhx_license key has the empty value or it's not added to the web.config Scheduler .NET will work in the trial mode (fully functional within 30 days of the build date).
  • If you specify the invalid key or the trial period has passed Scheduler .NET will throw an exception once an instance of DHXScheduler is created.


If the license key does not pass the validation, the component throws an exception. The exception message usually contains the error description:

  • Evaluation period has expired - is thrown after 30 days from the build date.
  • Invalid license string - value of 'dhx_license' was not recognized as a license string of dhtmlxScheduler. It may mean that you've missed it with some other value, like customer key for support system.
  • Failed to check credentials - the component was not able to verify the license key. This can happen if you've did not copied all characters of license key, or put some extra character, or modified key some other way.
  • Invalid credentials - this usually happens if key has been modified or it's not genuine.

If the problem can not be solved - feel free to contact DHTMLX support team at or notify us via email

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