I am trying to run webdriverio on my windows 10 computer and keep running into the same issue when trying to run my test js file. So I run this -jar /your/download/dir
(2020 Update)
If you are runnning Selenium Server 4 Alpha, you don't need to set chromedriver.exe path via command line, just make sure that the chromedriver exe file is in the same folder as the jar file
It took me quite a bit to figure out that Selenium Server does not include webdrivers (Firefox, Chrome, etc.) by default, they need to be downloaded separately.