Known Issues with 3rd Party Software
This is a list of known & reported problems with CSS HTML Validator and 3rd party software. Unfortunately, third party software if too often the cause of user difficulties with CSS HTML Validator (other software can be affected as well).
Software that is Reported to (currently or in the past) Interfere or Cause Problems with CSS HTML Validator:
* Bitdefender Total Security 2015 (reported 2016-01-05): may cause CSS HTML Validator not to run if not turned off
* Invisible Browsing from Amplusnet (reported 2011-09-01): may cause CSS HTML Validator to dump out of memory & disappear when starting
* Online Armor Free (reported 2011-04-27): causes access violation at startup; configure Online Armor to allow CSS HTML Validator
* PC Tools Spyware Doctor (reported 2011-11-19 & 2011-05-23): causes access violations and/or "CSS HTML Validator Editor has encountered a problem and needs to close." messages
* Sophos protection (reported 2010-07-13): causes installation failure (i.e. "Unable to create a temporary file. Setup aborted. Error 5: Access is denied."); disable protection to install
* SysInternals tools, including DiskMon, may trigger the software protection system to not let CSS HTML Validator run
* Zone Alarm may cause various issues from incorrect installation to CSS HTML Validator freezing
* IObit Malware Fighter may cause "a monitor program is running in your system" message
* Webroot SecureAnywhere may break copy & paste (this post about disabling Webroot SecureAnywhere's Identity Shield may help)
What to do?
* If you are running security software, try to temporarily disable it to see if that will solve the problem. You may also want to set it to ignore CSS HTML Validator or CSS HTML Validator's installation folder.
* Consider using the free Windows Defender or Microsoft Security Essentials (MSE). We haven't had any reports of problems due to these, and they're some of the better tested and more widely used anti-malware/anti-virus programs.
* Security software is in constant flux, so one day it may cause problems and another day (after an update) it may not
* Anti-virus and security software may interfere with the installation of CSS HTML Validator (as well as other software)