FRM-92100 when running a long running report

Users were experiencing the FRM-92100 with IllegalArgumentException while running a long running report, after investigation it was found that Request Timeout (seconds) value was 600 only on OHS.  So changing to 1500 resolved the issue.

There can be many other reason for this error so you can try this workaround also.
Try below work around:

1) FRM-92100 occurs when invoking a new forms session from existing form session, or another URL is invoked from the parent browser window of the forms applet?

To work-around use the applet parameter separateFrame="True". This parameter is set in the static html file or formsweb.cfg

2) If using Oracle Jinitiator, try clearing the Jinitiator JAR or jcache:

For versions 1.3.x.x.x : Control Panel - Jinitiator Control Panel - Cache Tab Page - Clear JAR Cache button

3) If using MS Internet Explorer check that permissions / security options are set correctly

Launch Microsoft Internet Explorer.
Select the Tools -> Internet Options from the top level menu.
Click the SECURITY Tab:
Choose Local Intranet Zone from the list.
Click Custom Level.
Select Java Permissions - Custom from the list.
Click Java Custom Settings.
Select the Edit Permissions tab.
Choose Enable for Run Unsigned Content.
Choose Enable for Run Signed Content.
Select the ADVANCED tab.
Scroll down to Java VM.
Check the Java console enabled option.
Select the CONNECTIONS tab.
Click the LAN Settings button.
If IE is using a proxy server : Check the Bypass proxy server for local addresses check box. Click the Advanced button, and enter the local domain in the Exceptions box. Use the form *.domain.com, where domain.com maps to your local domain.
Click OK to exit the dialog.
Click OK to save the changes and exit IE.
Restart the computer.

4) Has the formsweb.cfg applet parameter workingDirectory been changed recently?

The following lines may appear in the Java Console Output:

CMa3iK no proxyoracle.forms.net.ConnectionException:Forms session
<1> failed during startup: no response from runtime process at
oracle.forms.net.ConnectionException.createConnect ionException(Unknown
Source) at oracle.forms.net.HTTPNStream.getResponse(Unknown Source)...

accompanied by lines like those below in the Jserv.log or OC4J_BI_Forms server.log:

[26/11/2002 19:42:17:921 GMT+05:30] Forms session <1> aborted: runtime process failed during startup with errors
Unable to switch to Working Directory:d:\test;d:\f60

Forms session <11> aborted: runtime process failed during startup with errors
Unable to switch to Working Directory:

If so set the workingDirectory parameter to a single, accessible, directory instead of a directory list or a non-accessible directory.