This might probably indicate a mistake in the .jar file.
It contains a META-INF/services/org.eclipse.jetty.http.HttpFieldPreEncoder entry, which, according to the jar service provider interface specification, must contain the name of a class in the same .jar file which implements the interface org.eclipse.jetty.http.HttpFieldPreEncoder.
But, as the exception states, that service descriptor file contains org.eclipse.jetty.http.Http1FieldPreEncoder, a class that does not exist in the .jar file.
There is, however, a org.seleniumhq.jetty9.http.Http1FieldPreEncoder class in the .jar.
The easiest way to fix this is:
Extract the entire .jar to a temporary directory.
Change META-INF/services/org.eclipse.jetty.http.HttpFieldPreEncoder so it contains the single line org.seleniumhq.jetty9.http.Http1FieldPreEncoder.
Create a new .jar file from the changed content.
Hope this helps!