Android Studio Start Failed - Classnotfoundexception: Com.intellij.ide.plugins.pluginmanager

After installing Android Studio on a new Win8.1x64 machine, whenever I try to launch it I get a ClassNotFoundException: com.intellij.ide.plugins.PluginManager and Studio does not s

Solution 1:

For anyone who has a similar problem, the errors were caused by antivirus software (in this case Avast). After uninstalling it I was able to normally install and start Android Studio. I'm not sure exactly what is happening between Avast and Android Studio, but this solved the problem.

Also, I installed Avast back and now I get multiple IllegalStateExceptions and NullPointerExceptions in the Android Studio Event Log, but these do not interfere with working in AS normally.