Hello, Our system is VPS running CentOS release 5.8 with Plesk Panel 10.4.4 installed through a hosting service provider. My main question is whether I can do a PCRE update on the system; or if that would mess up the system? Alternatively, I saw some posts on the Parallels forum that dealt with setting up and running two versions of PHP. But then in the Plesk panel 11.0.9 upgrade pre-check I thought I saw a check saying there was not two versions of PHP running with an ok after the test - so that makes me wonder if there is a problem running two versions of PHP. (Unfortunately I didn't save the contents of that file and I don't see those checks run on subsequent tries to upgrade the Plesk panel.) Finally, the hosting service provider is suggesting that I can solve the PCRE problem by moving to cPanel. Does Parallels have a good solution keeping the Plesk panel in place? Background is below: 1. We tried to install some software and it was having problems. The response from their support personnel was: My apologies for the late response. I have reviewed the available information and have determined that it is indeed the built-in PCRE engine used by PHP that is out of date. According to phpinfo(), the library used is extremely old; it's 6.6 from February 2006. The only possible way that this could have happened is if PHP were deliberately configured and compiled with an older version of the library; by default, the bundled PCRE library's version should be according to the table shown here: http://www.php.net/manual/en/pcre.installation.php Your best option is to contact the systems administrator of the web hosting service and demand that a better build of PHP be made available. What is there currently is a highly abnormal PHP build, and I do not doubt that you would run into further problems if you attempted to use [our sofware] with PHP the way that it is. 2. We put in a ticket with our hosting service provider asking if we could get PCRE upgraded. Their response was: Our apologies but the version of PHP that is currently configured on your VPS was generated by Plesk and is specifically designed by the Parallels company to operate properly with the Plesk system. Because of this we are unfortunately not able to provide manual updates to PHP on Plesk systems. If you need to use software the requires a more recent version of PCRE you may want to look at switching to a cPanel VPS as cPanel does tend to use more up to date software versions (the current PCRE version for cPanel servers is 8.21, built on 2011-12-12). 3. After that I decided to try to upgrade to Plesk panel 11.0.9 to see if that might help with the PCRE version installed. That upgrade failed. (A different problem - it looks like it was looking update the Sitebuilder MySQL user password and failed on that. We don't have Sitebuilder installed.) 4. I contacted our hosting service provider about the failure of the Plesk panel upgrade and told them: ... (3:49:14pm)Me:I was thinking of going on the Parallels forum to address the question of PCRE, but thought it might be best to be at the current stable build before submitting a question that might be taken care of. (3:51:14pm)Support:I apologize, I have to recommend cPanel also. (3:51:36pm)Me:so you're saying a Plesk upgrade won't help? (3:52:26pm)Support:That is correct. Thanks for any suggestions.