Compilation error viewing the site on Plone 4.3.19

Hi Everyone! I upgraded an old Plone site to 4.3.19 (starting from 3.1.2). The process seems fine, I can even enter the "manage_main" and navigate through the components and different parts. The problem is that when trying to visualize the site I get the next error:

I've never got anything similar, so again (as in other posts) I'm lost. Is this error critical? Can you give any advice to solve it and get the site running?

Try to locate the template (main_template) and look at its line 6. Near this line, you should see a request.RESPONSE.setHeader. Somehow, this is wrong.
In the error message, we see u"python:request.RESPONSE.setHeader(\'...\',\'1". In this message the \ before the single quotes look strange (but this may be a representation bug); the next strangeness is that the header value and the function call are not terminated. Check the source code what really is at that place -- it likely should be u"python:request.RESPONSE.setHeader('X-XSS-Protection', '1')". Change the source that it looks like this (if it not already does).

It might be worth going to /portal_skins (after going to /manage_main) and the go to 'custom folder'. You might see a customised template here. Delete it (or rename it to 'name_copy" if you are unsure)

There is a typo in the of the Classic Theme and of the Unstyle theme. The issue is described here.

Some solutions:

  • In the ZMI in portal_skins override the from the theme you are using and fix the typo there.
  • Or in the skins control panel select Sunburst as your theme (but that will change the look of your site).
  • Or upgrade to Plone 4.3.20.

I'm really interested in the 4.3.20 option as security is the main priority of the group I'm working with. Where can I download this version? There's no link on the milestone page of

If you are looking for the Universal Installer, it will eventually appear here:
But there are some problems creating the installer in a way that works on all or most current platforms, so this is taking longer than usual.

If you are comfortable with Buildout, you can edit your buildout.cfg to extend instead of the 4.3.19 one.