[MCL-1153] Not being able to play

When ever I go into the new launcher to play, the play button is greyed out and when I checked the Console to see if anything was wrong I found this:

Unexpected exception refreshing version list
java.lang.IllegalArgumentException: Version '1.6.1' is already tracked
	at net.minecraft.launcher.updater.VersionList.addVersion(VersionList.java:91)
	at net.minecraft.launcher.updater.LocalVersionList.refreshVersions(LocalVersionList.java:44)
	at net.minecraft.launcher.updater.VersionManager.refreshVersions(VersionManager.java:47)
	at net.minecraft.launcher.Launcher$2.run(Launcher.java:166)
	at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
	at java.util.concurrent.FutureTask$Sync.innerRun(Unknown Source)
	at java.util.concurrent.FutureTask.run(Unknown Source)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
	at java.lang.Thread.run(Unknown Source)

NEED HELP FAST!!!!!