After upgrading to Windows 8 Pro 64 bit from Windows 7, every page which has Flash content produces this error message:
'The instruction at 0x71a30000 referenced memory at 0x71a30000. The memory could not be written.
Click on OK to terminate the program'
If there are several Flash videos, it produces this error message for each one.
This does not happen on Internet Explorer, Google Chrome, Opera, or Safari. However, I do all my web development on Firefox because of good third party tools, so this is a real problem for me.
Addendum: before I upgraded to W8 on my production machine, I tested it out on my test rig and a laptop. The flash plug-ins worked perfectly on these (same release), but they are both 32 bit machines.
You can check for problems caused by recent Flash updates and try these:
I disabled the protected mode as instructed, and the problem has resolved itself.