When trying to load activities in 8.x web, receive ClassFormatError.

When protected by Oracle Access Manager (OAM), P6 (also known as Web Access) users experience one of the following two issues: Prompted to re-authentication when loading any applet which 1. uses JavaScript Error: 'java.lang.ClassFormatError: Incompatible magic value <number> in class file <Applet>' when loading any applet which uses JavaScript.

Cause
By default, the ssoCookie:httponly challenge parameter is enabled in an authentication scheme. Enabling this parameter helps to prevent the JavaScript running in the browser from accessing the ObSSOCookie. This cookie provides a more secure environment. However, browser support for the ssoCookie:httponly challenge parameter is inconsistent and such inconsistency can cause Java applets to not run correctly -- failing with the two issues reported above.

If using Oracle Access Manager 11g:
If using OAM 11.1.1.3.0:
1. Stop the OAM server.
Edit the oam-config.xml file as follows:
<Setting Name="SSOCookieParam"
Type="xsd:string">disablehttponly</Setting>
2.
3. Save the file.
4. Start the OAM server.

Reference (Doc ID 1242418.1) on My Oracle Support