FULL PRODUCT VERSION :
For Windows 10:

java version "1.8.0_111"
Java(TM) SE Runtime Environment (build 1.8.0_111-b14)
Java HotSpot(TM) Client VM (build 25.111-b14, mixed mode)

For Ubuntu 14.04:

java version "1.8.0_111"
Java(TM) SE Runtime Environment (build 1.8.0_111-b14)
Java HotSpot(TM) 64-Bit Server VM (build 25.111-b14, mixed mode)


ADDITIONAL OS VERSION INFORMATION :
Windows 10 32 Bit Pro
Ubuntu 14.04 LTS 64 Bit Desktop

A DESCRIPTION OF THE PROBLEM :
In our company, we are using HTTP proxy with basic auth user authentication distributed via a proxy.pac configuration file.

If I try to open a website (IE or Firefox) containing a java application, since U111 and U112 we get an Java ClassNotFoundException. So the applett wont load. There is simply no pop up triggered which will ask you about your username and password. It happens OS indepently.

With Version U101 everything works as excepted.

If we set the proxy manually vie Java control panel, it tries to load the applets infinitely, because there is no option to pass a user and password over to Java at that Java control panel.

REGRESSION. Last worked in version 8u101

ADDITIONAL REGRESSION INFORMATION:
java version "1.8.0_101"
Java(TM) SE Runtime Environment (build 1.8.0_101-b13)
Java HotSpot(TM) Client VM (build 25.101-b13, mixed mode)


REPRODUCIBILITY :
This bug can be reproduced always.