diff --git a/install_nextcloud.sh b/install_nextcloud.sh
index a4bd369..8501b9a 100755
--- a/install_nextcloud.sh
+++ b/install_nextcloud.sh
@@ -22,19 +22,25 @@ clean_up() {
 
    if [[ -f "$_backup_crontab_file" ]]; then
 
-      echo "" >> $log_file
-      echo "# - (Re)Install previously saved crontab from '$_backup_crontab_file'" >> $log_file
-      echo "# -" >> $log_file
       echononl "(Re)Install previously saved crontab from '$_backup_crontab_file'.."
+      if [[ -n "$log_file" ]] ; then
+         echo "" >> $log_file
+         echo "# - (Re)Install previously saved crontab from '$_backup_crontab_file'" >> $log_file
+         echo "# -" >> $log_file
+         echo "crontab $_backup_crontab_file" >> $log_file
+         crontab $_backup_crontab_file >> $log_file 2>&1
+      else
+         crontab $_backup_crontab_file >> $err_log 2>&1
+      fi
 
-      echo "crontab $_backup_crontab_file" >> $log_file
-      crontab $_backup_crontab_file >> $log_file 2>&1
 
       if [[ $? -eq 0 ]]; then
          echo_ok
       else
          echo_failed
-         error "For more informations see log output at '$log_file'."
+         if [[ -n "$log_file" ]] ; then
+            error "For more informations see log output at '$log_file'."
+         fi
       fi
 
    fi
@@ -110,7 +116,6 @@ fatal (){
       echo "fatal: $*"
       echo "Script will be interrupted.."
    fi
-   echo ""
    clean_up 1
 }
 
@@ -196,7 +201,6 @@ blank_line() {
 
 
 
-
 # ----------
 # - Jobhandling 
 # ----------
@@ -1412,7 +1416,7 @@ if ! $INSTALL_COLABORA_SERVICE ; then
 	if $COLABORA_SERVICE_INSTALLED ; then
 		info "ColaboraOnline Service (loolwsd) is already installed."
 	else
-		warn "ColaboraOnline Service is not installed!"
+		warn "ColaboraOnline Service is not requested for installation!"
 	fi
 else
 
@@ -1428,9 +1432,9 @@ else
 	#apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 0C54D189F4BA284D >> $log_file 2>&1
 
    echo "wget -O /tmp/co-apt.key \\
-   https://www.collaboraoffice.com/repos/CollaboraOnline/CODE-centos7/repodata/repomd.xml.key" >> $log_file
+   https://collaboraoffice.com/downloads/gpg/collaboraonline-release-keyring.gpg" >> $log_file
    wget  -O /tmp/co-apt.key \
-      https://www.collaboraoffice.com/repos/CollaboraOnline/CODE-centos7/repodata/repomd.xml.key >> $log_file 2>&1
+       https://collaboraoffice.com/downloads/gpg/collaboraonline-release-keyring.gpg >> $log_file 2>&1
 
    if [[ "$?" -gt 0 ]]; then
       _failed=true
@@ -1539,7 +1543,7 @@ EOF
 	done
 
    if $_failed ; then
-      error "Something went wrong with installing debian packages .."
+      error "Something went wrong with installing debian packages (ColaboraOnline).."
 
       echononl "continue anyway [yes/no]: "
       read OK
@@ -1705,17 +1709,24 @@ EOF
 
    blank_line
 
-   if $apache2_installed ; then
-
-      # - Create Apache2 vhost configuration for ColaboraOnline service
-      # -
-      if  [[ -e "/var/lib/dehydrated/certs/${HOSTNAME_CO}/fullchain.pem" ]]; then
-         server_cert="/var/lib/dehydrated/certs/${HOSTNAME_CO}/fullchain.pem"
-         server_key="/var/lib/dehydrated/certs/${HOSTNAME_CO}/privkey.pem"
-      else
+   # - Check if regular certificates for ${HOSTNAME_CO} already present
+   # -
+   if  [[ -e "/var/lib/dehydrated/certs/${HOSTNAME_CO}/fullchain.pem" ]]; then
+      server_cert="/var/lib/dehydrated/certs/${HOSTNAME_CO}/fullchain.pem"
+      server_key="/var/lib/dehydrated/certs/${HOSTNAME_CO}/privkey.pem"
+   else
+      if $apache2_installed && [[ -f "/usr/local/apache2/conf/server-bundle.crt" ]] \
+         && [[ -f "/usr/local/apache2/conf/server.key" ]] ; then
          server_cert="/usr/local/apache2/conf/server-bundle.crt"
          server_key="/usr/local/apache2/conf/server.key"
+      else
+         server_key="/etc/ssl/private//etc/ssl/private"
+         server_cert="/etc/ssl/certs/ssl-cert-snakeoil.pem"
       fi
+   fi
+
+   if $apache2_installed ; then
+
 
       if [[ -d "$apache_vhost_dir" ]] ; then
 
@@ -1871,9 +1882,200 @@ EOF
 
          COLABORA_SERVICE_INSTALLED=true
       fi
-   else
-      warn "ColaboraOnline for webserver 'Nginx' not yet implemented"
+   elif $nginx_installed ; then
+      
+      if [[ -d "$nginx_vhost_dir" ]]; then
+
+         # - Remove symlink for nginx vhost file (if exists)
+         # -
+         if [[ -h "${nginx_vhost_enabled_dir}/${HOSTNAME_CO}.conf" ]]; then
+            
+            echo "" >> $log_file
+            echo "# - Remove existing Symlink '${nginx_vhost_enabled_dir}/${HOSTNAME_CO}.conf'" >> $log_file
+            echo "# -" >> $log_file
+            echononl "Remove existing Symlink '${nginx_vhost_enabled_dir}/${HOSTNAME_CO}.conf'" >> $log_file
+
+            echo "rm -f \"${nginx_vhost_enabled_dir}/${HOSTNAME_CO}.conf\""  >> $log_file
+            rm -f "${nginx_vhost_enabled_dir}/${HOSTNAME_CO}.conf" >> $log_file 2>&1
+
+            if [ "$?" = 0 ]; then
+               echo_ok
+            else
+               echo_failed
+               error "For more informations see log output at '$log_file'."
+
+               echononl "continue anyway [yes/no]: "
+               read OK
+               OK="$(echo "$OK" | tr '[:upper:]' '[:lower:]')"
+               while [[ "$OK" != "yes" ]] && [[  "$OK" != "no" ]] ; do
+                  echononl "Wrong entry! - repeat [yes/no]: "
+                  read OK
+               done
+               [[ $OK = "yes" ]] || fatal "Interrupted ny user."
+            fi
+
+         fi # if [[ -h "${nginx_vhost_enabled_dir}/${HOSTNAME_CO}.conf" ]]; then
+
+         # - Backup nginx vhost file if exists
+         # -
+         if [[ -f "${nginx_vhost_dir}/${HOSTNAME_CO}.conf" ]]; then
+
+            echo "" >> $log_file
+            echo "# - Backup existing file '${nginx_vhost_dir}/${HOSTNAME_CO}.conf'" >> $log_file
+            echo "# -" >> $log_file
+            echononl "Backup existing file '${nginx_vhost_dir}/${HOSTNAME_CO}.conf'" >> $log_file
+
+            echo "mv \"${nginx_vhost_dir}/${HOSTNAME_CO}.conf\" \"${nginx_vhost_dir}/${HOSTNAME_CO}.conf.$backup_date\""  >> $log_file
+            mv "${nginx_vhost_dir}/${HOSTNAME_CO}.conf" "${nginx_vhost_dir}/${HOSTNAME_CO}.conf.$backup_date" >> $log_file 2>&1
+
+            if [ "$?" = 0 ]; then
+               echo_ok
+            else
+               echo_failed
+               error "For more informations see log output at '$log_file'."
+
+               echononl "continue anyway [yes/no]: "
+               read OK
+               OK="$(echo "$OK" | tr '[:upper:]' '[:lower:]')"
+               while [[ "$OK" != "yes" ]] && [[  "$OK" != "no" ]] ; do
+                  echononl "Wrong entry! - repeat [yes/no]: "
+                  read OK
+               done
+               [[ $OK = "yes" ]] || fatal "Interrupted ny user."
+
+            fi
+
+         fi # if [[ -f "${nginx_vhost_dir}/${HOSTNAME_CO}.conf" ]]
+
+         echo "" >> $log_file
+         echo "# - Create nginx vhost entry for '$HOSTNAME_CO'" >> $log_file
+         echo "# -" >> $log_file
+         echononl "Create nginx vhost entry for '$HOSTNAME_CO'"
+
+         cat<<EOF > "${nginx_vhost_dir}/${HOSTNAME_CO}.conf" 2>> $log_file
+   # --- $HOSTNAME_CO
+
+   # ---
+   # see: https://www.collaboraoffice.com/code/nginx-reverse-proxy/
+   # ---
+
+   server {
+      listen 443 ssl;
+      listen [::]:443 ssl;
+
+      server_name ${HOSTNAME_CO};
+
+      ssl_certificate ${server_cert};
+      ssl_certificate_key ${server_key};
+
+      # static files
+      location ^~ /loleaflet {
+         proxy_pass https://localhost:9980;
+         proxy_set_header Host \$http_host;
+      }
+
+      # WOPI discovery URL
+      location ^~ /hosting/discovery {
+         proxy_pass https://localhost:9980;
+         proxy_set_header Host \$http_host;
+      }
+
+      # Capabilities
+      location ^~ /hosting/capabilities {
+         proxy_pass https://localhost:9980;
+         proxy_set_header Host \$http_host;
+      }
+
+      # main websocket
+      location ~ ^/lool/(.*)/ws$ {
+         proxy_pass https://localhost:9980;
+         proxy_set_header Upgrade \$http_upgrade;
+         proxy_set_header Connection "Upgrade";
+         proxy_set_header Host \$http_host;
+         proxy_read_timeout 36000s;
+      }
+
+      # download, presentation and image upload
+      location ~ ^/lool {
+         proxy_pass https://localhost:9980;
+         proxy_set_header Host \$http_host;
+      }
+
+      # Admin Console websocket
+      location ^~ /lool/adminws {
+         proxy_pass https://localhost:9980;
+         proxy_set_header Upgrade \$http_upgrade;
+         proxy_set_header Connection "Upgrade";
+         proxy_set_header Host \$http_host;
+         proxy_read_timeout 36000s;
+      }
+   }
+EOF
+         if [ "$?" = 0 ]; then
+            echo_ok
+         else
+            echo_failed
+            error "For more informations see log output at '$log_file'."
+
+            echononl "continue anyway [yes/no]: "
+            read OK
+            OK="$(echo "$OK" | tr '[:upper:]' '[:lower:]')"
+            while [[ "$OK" != "yes" ]] && [[  "$OK" != "no" ]] ; do
+               echononl "Wrong entry! - repeat [yes/no]: "
+               read OK
+            done
+            [[ $OK = "yes" ]] || fatal "Interrupted ny user."
+         fi
+
+         # - Symlimk Nginx VHost file
+         # -
+         # -  '${nginx_vhost_enabled_dir}/${HOSTNAME_CO}.conf' --> '${nginx_vhost_dir}/${HOSTNAME_CO}.conf'
+         # -
+         _symlink_src="${nginx_vhost_dir}/${HOSTNAME_CO}.conf"
+         _symlink_dst="${nginx_vhost_enabled_dir}/${HOSTNAME_CO}.conf"
+         echo "" >> $log_file
+         echo "# - Symlink '${_symlink_dst}' --> ${_symlink_src}" >> $log_file
+         echo "# -" >> $log_file
+         echononl "Symlink '${_symlink_dst}' --> ${_symlink_src}"
+
+         ln -s "$_symlink_src" "$_symlink_dst" >> $log_file 2>&1
+         if [ "$?" = 0 ]; then
+            echo_ok
+         else
+            echo_failed
+            error "For more informations see log output at '$log_file'."
+
+            echononl "continue anyway [yes/no]: "
+            read OK
+            OK="$(echo "$OK" | tr '[:upper:]' '[:lower:]')"
+            while [[ "$OK" != "yes" ]] && [[  "$OK" != "no" ]] ; do
+               echononl "Wrong entry! - repeat [yes/no]: "
+               read OK
+            done
+            [[ $OK = "yes" ]] || fatal "Interrupted ny user."
+
+         fi
+
+      else
+
+         error "Cant find nginx's vhost directory!"
+
+         echononl "continue anyway [yes/no]: "
+         read OK
+         OK="$(echo "$OK" | tr '[:upper:]' '[:lower:]')"
+         while [[ "$OK" != "yes" ]] && [[  "$OK" != "no" ]] ; do
+            echononl "Wrong entry! - repeat [yes/no]: "
+            read OK
+         done
+         [[ $OK = "yes" ]] || fatal "Interrupted ny user."
+
+
+      fi # if [[ -d "$nginx_vhost_dir" ]]
+
+
+
    fi # if $apache2_installed
+
 fi
 
 
@@ -4175,9 +4377,9 @@ elif $nginx_installed ; then
       fi
 
       echo "" >> $log_file
-      echo "# - Create apache vhost entry for '$WEBSITE'" >> $log_file
+      echo "# - Create nginx vhost entry for '$WEBSITE'" >> $log_file
       echo "# -" >> $log_file
-      echononl "Create apache vhost entry for '$WEBSITE'"
+      echononl "Create nginx vhost entry for '$WEBSITE'"
 
       cat<<EOF > "${nginx_vhost_dir}/${WEBSITE}.conf" 2>> $log_file
 # --- $WEBSITE