I replaced some of the files under "/opt/gluu-server-3.1.5/opt/jdk1.8.0_181/jre/lib/security/" and were not able to load the gluu login page anymore. So I uninstalled gluu using these commands as per online instructions: **service gluu-server-3.1.5 stop apt-get remove gluu-server-3.1.5 rm -rf /opt/gluu-server-3.1.5.save** Then I rebooted the VM and tried re-installing it by: **apt-get install gluu-server-3.1.5** that I get this error: **Setting up gluu-server-3.1.5 (1-15~xenial+Ub16.04) ... update-rc.d: error: initscript does not exist: /etc/init.d/gluu-server-3.1.5 dpkg: error processing package gluu-server-3.1.5 (--configure): subprocess installed post-installation script returned error exit status 1 E: Sub-process /usr/bin/dpkg returned an error code (1)** What did I do wrong and how can I fix it? Thanks in advance Update: I also tried all[ 4 commands for ubuntu 16](https://gluu.org/docs/ce/3.1.5/installation-guide/install/#ubuntu-server-1604x) to install gluu and got the same error.