Microsoft Edge WebDriver - Unexpected error. Unknown error

Question

I am getting the following exception when trying to get Microsoft Edge automation to work with Selenium:

OpenQA.Selenium.WebDriverException: Unexpected error. Unknown error

I am using the Selenium.WebDriver.MicrosoftDriver NuGet package, version 17.17134.0.

My code is simply the constructor:

var driver = new EdgeDriver();

I have tried various overloads that are suggested:

var driver = new EdgeDriver(new EdgeOptions());

var driver = new EdgeDriver(pathToMicrosoftWebDriverExecutable);

No luck. I made sure that the WebDriver version from Microsoft matched the Edge version on the machine running the tests.

Is there any way I can get a more informative error message here? Note that all Selenium unit tests work as expected with both the Firefox and Chrome WebDrivers, it's only Edge that won't work.

Answer 1

I know you mentioned you had the same versions, but I was getting the same error myself and this is how I resolved it so hopefully this helps.

It appears that Microsoft is no longer releasing the Web Driver as a standalone version, which may be the issue. (See here for more details) Currently, Edge seems to be at version 17763, whereas the NuGet package is 17134. So what I had to do was go in and "install it as a standalone by going to Settings > Apps > Apps & features > Manage optional features." There are some alternative directions that are included in the link above.

Once that installed I pointed the driver to the location and it finally worked.

var driver = new EdgeDriver("C:\\Windows\\System32\\", edgeOptions);