Hello
As explained in an other answer to you, you can use our solution center:
https://solutions.industrysoftware.automation.siemens.com/result.php?sort=desc&p=1&q=%22ERROR%3A+Unhandled+exception%3A+0xc0000005%22
But quickly going through the results from there. It is a pretty general error. It is always useful to know more about the contect... What are you doing at the time of the error. What is NX doing just before the error? (You might know more from the lines that proceed to this error.)
Or report this issue to GTAC, upload the syslog file of the session and the details you know around this issue.
I hope this helps.
Kind regards,
Dennis