This is not strictly an ispconfig issue, but I have exhausted all my google skills trying to resolve this issue. I have an ubuntu 14.04 with nginx and ispconfig 3.1.15 Currently running PHP 5.5.9 and 5.6.35 I tried to install PHP7.4 following the instructions here https://www.howtoforge.com/tutorial/how-to-compile-and-install-php-7.4-on-ubuntu-18-04/ which worked on Ubuntu 16.04. When I try to compile I get an error: Code: checking whether to enable input filter support... yes checking whether to enable FTP support... yes checking whether to explicitly enable FTP SSL support... no checking for openssl >= 1.0.1... yes checking for GD support... yes checking for external libgd... no checking for libwebp... no checking for libjpeg... yes checking for libXpm... no checking for FreeType 2... yes checking whether to enable JIS-mapped Japanese font support in GD... no checking for fabsf... yes checking for floorf... yes checking for zlib... yes checking for libpng... yes checking for libjpeg... no configure: error: Package requirements (libjpeg) were not met: No package 'libjpeg' found Consider adjusting the PKG_CONFIG_PATH environment variable if you installed software in a non-standard prefix. Alternatively, you may set the environment variables JPEG_CFLAGS and JPEG_LIBS to avoid the need to call pkg-config. See the pkg-config man page for more details. I found libjpeg here: Code: [email protected]:/$ locate libjpeg /usr/lib/debug/usr/lib/x86_64-linux-gnu/libjpeg.so.62.0.0 /usr/lib/x86_64-linux-gnu/libjpeg.a /usr/lib/x86_64-linux-gnu/libjpeg.so /usr/lib/x86_64-linux-gnu/libjpeg.so.62 /usr/lib/x86_64-linux-gnu/libjpeg.so.62.0.0 /usr/lib/x86_64-linux-gnu/libjpeg.so.8 /usr/lib/x86_64-linux-gnu/libjpeg.so.8.0.2 I did this: export PKG_CONFIG_PATH=/usr/lib/x86_64-linux-gnu and tried to run the ./configure but got same error. I did this: export PKG_CONFIG_PATH=/usr/lib/pkgconfig and tried to run the ./configure but got same error. I have searched google high and low but can't find anything relevant (that I can see at least). I even tried to install 7.4 from ondrej ppa (https://www.cyberciti.biz/faq/ubuntu-linux-14-04-install-php7-using-apt-get-command/) but couldn't find php7 (apt-cache search php7), only php5 Would really be grateful if someone can point me in the right direction. Thanks!