For me it does not crash always but sometimes, usually when I scroll some page where youtube video is embedded: when it appears in visible area, it may crash; its not 100% reproducible but happens very often and is very annoying.

Unfortunately it does not give useful information after the crash, just "Application: nspluginviewer (nspluginviewer), signal: Segmentation fault" (I have kdebase-dbg installed). It would be useful if somebody tells how to debug this.

I use KDE 4.6.5.

Nspluginviewer crashes (sometimes) when I go from some webpage to its subpage or back. This happens on two computers:

Computer 1:
board                          D845GEBV2
processor                      Intel(R) Pentium(R) 4 CPU 2.80GHz
kernel-PAE.i686                3.2.7-1.fc16
kdebase.i686                   6:4.7.4-2.fc16
flash-plugin.i386              11.1.102.62-release

Excerpt from root messages:
Feb 23 14:15:08 grin abrt[6182]: Saved core dump of pid 6160 (/usr/bin/nspluginviewer) to /var/spool/abrt/ccpp-2012-02-23-14:15:07-6160 (30715904 bytes)
Feb 23 14:15:08 grin abrtd: Directory 'ccpp-2012-02-23-14:15:07-6160' creation detected
Feb 23 14:15:09 grin abrtd: Blacklisted executable '/usr/bin/nspluginviewer'
Feb 23 14:15:09 grin abrtd: 'post-create' on '/var/spool/abrt/ccpp-2012-02-23-14:15:07-6160' exited with 1
Feb 23 14:15:09 grin abrtd: Corrupted or bad directory /var/spool/abrt/ccpp-2012-02-23-14:15:07-6160, deleting

Computer 2:
board                          DH61CR
processor                      Intel(R) Pentium(R) CPU G620 @ 2.60GHz
kernel.x86_64                  3.2.7-1.fc16
kdebase.x86_64                 6:4.7.4-2.fc16
flash-plugin.x86_64            11.1.102.62-release

Excerpt from root messages:
Feb 25 22:01:26 mozart abrtd: Directory 'ccpp-2012-02-25-22:01:25-4025' creation detected
Feb 25 22:01:26 mozart abrt[4048]: Saved core dump of pid 4025 (/usr/bin/nspluginviewer) to /var/spool/abrt/ccpp-2012-02-25-22:01:25-4025 (154181632 bytes)
Feb 25 22:01:26 mozart abrtd: Blacklisted executable '/usr/bin/nspluginviewer'
Feb 25 22:01:26 mozart abrtd: 'post-create' on '/var/spool/abrt/ccpp-2012-02-25-22:01:25-4025' exited with 1
Feb 25 22:01:26 mozart abrtd: Corrupted or bad directory /var/spool/abrt/ccpp-2012-02-25-22:01:25-4025, deleting

Note 1:
The crash is common on the computer 1 (32 bit) and rare on computer 2 (64 bit).

Note 2:
There has been no such crash by Fedora 11 and 12 (computer 2). However, the file  
libflashplayer.so was then put manually in the directory HOME/mozilla/plugins, while now it is installed by yum.

Note 3:
Maybe this is another unrelated problem, but on some webpages it is not possible to play a video, as the webpage requires first to install flashplayer.

Thanks, Vlado

Cannot reporduce this crash with KDE 4.8.2 and flash player plugin 
flash player plugin 11.1 has known issues causing crashes all over the place in Qt based browsers on both 32 and 64 bit environments. You might want to update to flash player 11.2 first and see if the issue gets resolved by that.

Please, see also the bug 297457.
The crash continues to appear on computer 1 with the software
kernel-PAE.i686             3.3.2-1.fc16
kde-runtime.i686            4.8.2-1.fc16
flash-plugin.i386           11.1.102.63-release
but it has completely disappeared on computer 2.
As for the flash-plugin 11.2, I did not install it on computer 1, as on computer 2 it fails to work: the videos are pushed into blue color and after clicking for the full screen display the computer freezes (this happens in firefox, but only for the videos from youtube).
I had to reinstall the version 11.1.102.63 (manually), because adobe supports only the
newest version. Therefore I think that the problem is not caused by the flash-plugin.
Please, try to reproduce the crash on the webpages www.pravda.sk, spravy.pravda.sk and on its subpages (containing particular news).

Dear Bug Submitter,

This bug has been stagnant for a long time. Could you help us out and re-test if the bug is valid in the latest version? I am setting the status to NEEDSINFO pending your response, please change the Status back to REPORTED when you respond.

Thank you for helping us make KDE software even better for everyone!

Dear Bug Submitter,

This is a reminder that this bug has been stagnant for a long time. Could you help us out and re-test if the bug is valid in the latest version? This bug will be moved back to REPORTED Status for manual review later, which may take a while. If you are able to, please lend us a hand.

Thank you for helping us make KDE software even better for everyone!

Flash and Netscape plugins are no longer supported.