I have this problem when trying to upgrade the system and then starts Dovecot. The process ask me about preserving my config file; I answer "YES" and then it breaks. I know this is not a new problem but I don't know the right way to solve this for ISPC. I have found comments of people recommending a new Dovecot install, although I have clamav disabled and some modifications in headers, etc.. I'm not sure on this. What's the best way to solve this problem? Code: # apt-get upgrade Reading package lists... Done Building dependency tree Reading state information... Done Calculating upgrade... Done 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded. 8 not fully installed or removed. After this operation, 0 B of additional disk space will be used. Do you want to continue? [Y/n] Setting up dovecot-core (1:2.2.27-3+deb9u4) ... ucfr: Attempt from package dovecot-core to take /etc/dovecot/dovecot.conf away from package 4:4:4:4:4:4:4:4:4:4:4:4:4:4:4:4:4:4:4:4:4:4:4:4:4:4:4:4:dovecot-core ucfr: Aborting. dpkg: error processing package dovecot-core (--configure): subprocess installed post-installation script returned error exit status 4 dpkg: dependency problems prevent configuration of dovecot-lmtpd: dovecot-lmtpd depends on dovecot-core (= 1:2.2.27-3+deb9u4); however: Package dovecot-core is not configured yet. dpkg: error processing package dovecot-lmtpd (--configure): dependency problems - leaving unconfigured dpkg: dependency problems prevent configuration of dovecot-mysql: dovecot-mysql depends on dovecot-core (= 1:2.2.27-3+deb9u4); however: Package dovecot-core is not configured yet.