Disabling open_basedir is the simplest solution, but you could alternatively include all paths that Blesta must access. Off the top of my head, the install directory, the uploads directory, the temp directory (/tmp/) to start. phpseclib also tries to access /dev/random, /dev/urandom for encryption purposes. It's easier to leave open_basedir disabled, but that's up to you. We also recommend running Blesta on its own server (A VPS will do) without any other applications, but many run in it a share