How to find out WHY Flash Player 11.2.202.236 plugins crash in Firefox ESR 10.0.6 on 64-bit Linux

Question

Flash crashes dozens of times a day and I am trying to figure out WHY.
I have the recommended latest player & browser for my operating system.
The only diagnostic information I have is that the crashes seem to occur when a few tabs are open with videos loading in them and when any one video is closed, flash then locks up the browser for about 30 seconds, and then ALL the videos that were loading in separate tabs are dumped & say that the plugin crashed.
Details about the system from http://helpx.adobe.com/flash-player.html
1. Flash player version: 11.2.202.236
2. Operating System: Linux 2.6.32-279.2.1.el6.x86_64 (64-bit)
3. Browser: Firefox Firefox ESR 10.0.6
This is the correct set of components.
Debugging, I've modified the about:config dom.ipc.plugins.timeoutSecs to any value of 10 seconds to 45 seconds (the default), but it doesn't seem to make a difference in the number of crashes.
Any idea how to get more diagnostic information?

Answer 1

Unfortunately, there's nothing in "/var/crash" after the numerous flash crashes so I'm not sure where to look next.
The 'dmesg' command reports:
npviewer.bin[16884]: segfault at 340 ip 00007f26bda22ab0 sp 00007fffa8abbe78 error 6 in libflashplayer.so[7f26bd68d000+1179000]
Bringing up the CentOS 6 "Applications->System Tools->System Monitor", I see the numerous Flash crashes appear to have some relationship with "npviewer.bin", which uses the "/usr/lib64/flash-plugin/libflashplayer.so" shared object module and which has numerous "open files", one of which is "/home/<username>/.xsession-errors".
Looking at "/home/<username>/.xsession-errors", we find these lines, which may be useful.
Here are some excerpted errors & warnings:
*** NSPlugin Viewer  *** WARNING: unhandled variable 18 (<unknown variable>) in NPN_GetValue()
NOTE: child process received `Goodbye', closing down
failed to create drawable
(firefox:5813): Gtk-CRITICAL **: gtk_clipboard_set_with_data: assertion `targets != NULL' failed
NOTE: child process received `Goodbye', closing down
(firefox:5813): Gtk-CRITICAL **: gtk_clipboard_get_for_display: assertion `!display->closed' failed
failed to create drawable
*** NSPlugin Viewer  *** WARNING: unhandled variable 18 (<unknown variable>) in NPN_GetValue()
Failed to open VDPAU backend libvdpau_nvidia.so: cannot open shared object file: No such file or directory
Gdk-ERROR **: The program 'npviewer.bin' received an X Window System error.
This probably reflects a bug in the program.
The error was 'BadMatch (invalid parameter attributes)'.
  (Details: serial 857 error_code 8 request_code 140 minor_code 3)
  (Note to programmers: normally, X errors are reported asynchronously;
   that is, you will receive the error a while after causing it.
   To debug your program, run it with the --sync command line
   option to change this behavior. You can then get a meaningful
   backtrace from your debugger if you break on the gdk_x_error() function.)
aborting...
*** NSPlugin Wrapper *** ERROR: NPP_HandleEvent() wait for reply: Connection closed
*** NSPlugin Wrapper *** WARNING:(../src/npw-wrapper.c:2537):invoke_NPP_HandleEvent: assertion failed: (rpc_method_invoke_possible(plugin->connection))
*** NSPlugin Wrapper *** ERROR: NPObject 0x7f71eb734a00 is no longer valid!                                                                                                                                                                93,43          0%
Q: Where do we look to find the cause of numerous flash crashes on Linux?