Hi, i'd like to install an additional PHP 5.3.29 under Ubuntu 16.04 to run older websites. When i run MAKE etc. i get error "configure: error: undefined reference to `client_errors'
Most likely the openSSL lib from Ubunru 16.04 is too new for PHP 5.3, so you will have to compile your own one. The compile script from Marus might help you here: https://www.howtoforge.com/community/threads/problem-with-link.76759/page-2#post-362076