Upgrade to 3.2.1: Error in StylesheetUIAssetMerger.php

I did the one click upgrade and got this error, uninstalled listed plugins and vm restart also, i think the previous version was 3.1.0
After upgrade i get this error:

The following error just broke Piwik (v3.2.1):

variable @theme-color-header-text is undefined: failed at color: @theme-color-header-text !important; line: 1209

C:\inetpub\wwwroot\piwik\core\AssetManager\UIAssetMerger\StylesheetUIAssetMerger.php line 48

Before clearing cache i had this error:
An exception has been thrown during the rendering of a template (“variable @theme-color-header-text is undefined: failed at color: @theme-color-header-text !important; line: 1209”). in C:\inetpub\wwwroot\piwik\plugins\CoreHome\templates\getDefaultIndexView.twig 7 using PHP 5.6.30


This variable should be set in plugins/Morpheus/stylesheets/theme.less. Can you try to replace the Piwik files with the latest ones to check if they got broken during the update?

Thanks that helped!

before manual update checked the file and it had this line:
@theme-color-header-text: @color-white;