I have the same problem. When I disable the chromedriver plugin, I can get my node up and running but with the plugin I get:
...
Installing chromedriver to /var/jenkins/tools/chromedriver
ERROR: Unexpected error in launching a slave. This is probably a bug in Jenkins.
java.lang.NullPointerException
at org.jenkinsci.plugins.chromedriver.DownloadableImpl.getType(DownloadableImpl.java:91)
at org.jenkinsci.plugins.chromedriver.DownloadableImpl.select(DownloadableImpl.java:78)
at org.jenkinsci.plugins.chromedriver.DownloadableImpl.resolve(DownloadableImpl.java:35)
at org.jenkinsci.plugins.chromedriver.ComputerListenerImpl.process(ComputerListenerImpl.java:43)
at org.jenkinsci.plugins.chromedriver.ComputerListenerImpl.preOnline(ComputerListenerImpl.java:34)
at hudson.slaves.SlaveComputer.setChannel(SlaveComputer.java:370)
at hudson.slaves.SlaveComputer.setChannel(SlaveComputer.java:317)
at hudson.plugins.sshslaves.SSHLauncher.startSlave(SSHLauncher.java:454)
at hudson.plugins.sshslaves.SSHLauncher.launch(SSHLauncher.java:293)
at hudson.slaves.SlaveComputer$1.call(SlaveComputer.java:200)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
at java.util.concurrent.FutureTask.run(FutureTask.java:166)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
at java.lang.Thread.run(Thread.java:679)

Is there a fix or workaround?

Same issue for me,

Installing chromedriver to /var/lib/jenkins/slaves/tools/chromedriver
ERROR: Unexpected error in launching a slave. This is probably a bug in Jenkins.
java.lang.NullPointerException
	at org.jenkinsci.plugins.chromedriver.DownloadableImpl.getType(DownloadableImpl.java:91)
	at org.jenkinsci.plugins.chromedriver.DownloadableImpl.select(DownloadableImpl.java:78)
	at org.jenkinsci.plugins.chromedriver.DownloadableImpl.resolve(DownloadableImpl.java:35)
	at org.jenkinsci.plugins.chromedriver.ComputerListenerImpl.process(ComputerListenerImpl.java:43)
	at org.jenkinsci.plugins.chromedriver.ComputerListenerImpl.preOnline(ComputerListenerImpl.java:34)
	at hudson.slaves.SlaveComputer.setChannel(SlaveComputer.java:370)
	at hudson.slaves.SlaveComputer.setChannel(SlaveComputer.java:317)
	at hudson.plugins.sshslaves.SSHLauncher.startSlave(SSHLauncher.java:454)
	at hudson.plugins.sshslaves.SSHLauncher.launch(SSHLauncher.java:293)
	at hudson.slaves.SlaveComputer$1.call(SlaveComputer.java:200)
	at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
	at java.util.concurrent.FutureTask.run(FutureTask.java:166)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
	at java.lang.Thread.run(Thread.java:679)
ERROR: Connection terminated

Added "chromedriver" component to the issue.

I just tried this plugin for the first time on 1.541

I get a "similar" but not the same error. I didn't want to creat a new Jira as it seems it may be similar.

Actions taken were...

-install plugin
-restart server
-during server startup, the following occurs...

Installing chromedriver to /var/lib/jenkins/tools/chromedriver
ERROR: Failed to install chromedriver
ha:(long string removed for clarity)=java.io.IOException: No installation data is downloaded from chromedriver yet
at org.jenkinsci.plugins.chromedriver.DownloadableImpl.select(DownloadableImpl.java:74)
at org.jenkinsci.plugins.chromedriver.DownloadableImpl.resolve(DownloadableImpl.java:35)
at org.jenkinsci.plugins.chromedriver.ComputerListenerImpl.process(ComputerListenerImpl.java:43)
at org.jenkinsci.plugins.chromedriver.ComputerListenerImpl.onOnline(ComputerListenerImpl.java:29)
at jenkins.model.Jenkins.<init>(Jenkins.java:849)
at hudson.model.Hudson.<init>(Hudson.java:82)
at hudson.model.Hudson.<init>(Hudson.java:78)
at hudson.WebAppMain$3.run(WebAppMain.java:222)