diff --git a/check_process b/check_process
index ce2bb9b..f8bad33 100644
--- a/check_process
+++ b/check_process
@@ -17,7 +17,7 @@
 		setup_public=1
 		upgrade=1
 #Last version
-		upgrade=1	from_commit=69b86b123ddb3b13e25f39df32bc17a872d67e5e
+		upgrade=1	from_commit=daf9f864b4f4adde4130c9d000ecc87f5d44ca42
 #v0.6.6
 #		upgrade=1	from_commit=11f5b96df7d8850beff47f9904745fa53a6f7ed9
 		backup_restore=1
diff --git a/conf/init_calibre_db_user b/conf/init_calibre_db_user
deleted file mode 100644
index 81e736d..0000000
--- a/conf/init_calibre_db_user
+++ /dev/null
@@ -1,3 +0,0 @@
-nickname=\'$admin\',
-locale=\'$language\',
-mature_content=0
\ No newline at end of file
diff --git a/scripts/_common.sh b/scripts/_common.sh
index 03f39a0..b3f726e 100644
--- a/scripts/_common.sh
+++ b/scripts/_common.sh
@@ -4,6 +4,6 @@ PKG_DEPENDENCIES="sqlite3 libldap2-dev libsasl2-dev python3-dev imagemagick pyth
 DOSSIER_MEDIA=/home/yunohost.multimedia
 
 #These var are used in init_calibre_db_settings conf file
-LOG_FILE=/var/log/$app/$app.log
-ACCESS_LOG_FILE=/var/log/$app/$app-access.log
+log_file=/var/log/$app/$app.log
+access_log_file=/var/log/$app/$app-access.log
 
diff --git a/scripts/install b/scripts/install
index e059794..791633a 100755
--- a/scripts/install
+++ b/scripts/install
@@ -27,12 +27,19 @@ public_library=$YNH_APP_ARG_PUBLIC_LIBRARY
 #when initializing the conf file of the app
 source _common.sh
 
-
 #if app is public, we assume library is public
 if [ $is_public -eq 1 ]; then
 	public_library=1
 fi
 
+if [ $is_public -eq 1 ]; then 						#app is public, library is public
+	calibre_dir=$DOSSIER_MEDIA/share/eBook
+elif [ $is_public -eq 0 ] && [ $public_library -eq 1 ]; then  #app is private, library is public
+	calibre_dir=$DOSSIER_MEDIA/share/eBook
+else 												#app is private, library is private
+	calibre_dir=$DOSSIER_MEDIA/$admin/eBook
+fi
+
 #=================================================
 # MANAGE SCRIPT FAILURE
 #=================================================
@@ -79,6 +86,12 @@ ynh_app_setting_set $app port $port
 #=================================================
 ynh_script_progression --message="Downloading sources to $final_path..." --weight=10
 ynh_app_setting_set $app final_path $final_path
+
+#Set settings constant initializer of the app
+ynh_add_config --template="../sources/patches/app-config_sql.py.patch.src" --destination="../sources/patches/app-config_sql.py.patch"
+ynh_add_config --template="../sources/patches/app-ub.py.patch.src" --destination="../sources/patches/app-ub.py.patch"
+ynh_add_config --template="../sources/patches/app-constants.py.patch.src" --destination="../sources/patches/app-constants.py.patch"
+
 # Download, check integrity, uncompress and patch the source from app.src
 ynh_setup_source "$final_path"
 
@@ -143,13 +156,6 @@ ynh_script_progression --message="Creating files and directory..." --weight=5
 ynh_multimedia_build_main_dir
 ynh_multimedia_addaccess $app
 
-if [ $is_public -eq 1 ]; then 						#app is public, library is public
-	calibre_dir=$DOSSIER_MEDIA/share/eBook
-elif [ $is_public -eq 0 ] && [ $public_library -eq 1 ]; then  #app is private, library is public
-	calibre_dir=$DOSSIER_MEDIA/share/eBook
-else 												#app is private, library is private
-	calibre_dir=$DOSSIER_MEDIA/$admin/eBook
-fi
 
 #Check if metadata.db file exists. If not create it (empty library)
 if [ ! -e "$calibre_dir"/metadata.db ]; then
@@ -177,20 +183,20 @@ ynh_script_progression --message="Setting up database and settings..." --weight=
 #we need to start and stop the service so that initial app.db file is created and that we can set default data
 #If port 8083 is already in use (ex for second instance), then service start will fail, which is expected : so we do not want
 #to set $port on the line match. "server on" will be displayed in case the port is already in use and should be ok to spot the fact that the database is initialized.
-ynh_systemd_action --service_name=$app --action="start" --line_match="Starting Gevent server on" --log_path="$final_path/calibre-web.log" -t 30
+#ynh_systemd_action --service_name=$app --action="start" --line_match="Starting Gevent server on" --log_path="$final_path/calibre-web.log" -t 30
 #sleep required on low spec like raspberryPi
-sleep 2s
+#sleep 2s
 #remove unwanted calibre-web.log
-ynh_secure_remove --file="$final_path/calibre-web.log"
-ynh_systemd_action --service_name=$app --action="stop"
+#ynh_secure_remove --file="$final_path/calibre-web.log"
+#ynh_systemd_action --service_name=$app --action="stop"
 
 
 #set database settings as per conf file
-conf="\"UPDATE settings SET $(. <(echo -E echo $(<../conf/init_calibre_db_settings))), $(. <(echo -E echo $(<../conf/init_calibre_db_ldap_settings))) WHERE ID=1\""
-eval sqlite3 $final_path/app.db "$conf"
+#conf="\"UPDATE settings SET $(. <(echo -E echo $(<../conf/init_calibre_db_settings))), $(. <(echo -E echo $(<../conf/init_calibre_db_ldap_settings))) WHERE ID=1\""
+#eval sqlite3 $final_path/app.db "$conf"
 
-conf="\"UPDATE user SET $(. <(echo -E echo $(<../conf/init_calibre_db_user))) WHERE ID=1\""
-eval sqlite3 $final_path/app.db "$conf"
+#conf="\"UPDATE user SET $(. <(echo -E echo $(<../conf/init_calibre_db_user))) WHERE ID=1\""
+#eval sqlite3 $final_path/app.db "$conf"
 
 #Update Imagick policy as per https://github.com/janeczku/calibre-web/wiki/FAQ#what-to-do-if-cover-pictures-are-not-extracted-from-pdf-files
 ynh_replace_string --match_string="<policy domain="coder" rights="none" pattern="PDF" />" \
@@ -204,7 +210,7 @@ ynh_replace_string --match_string="<policy domain="coder" rights="none" pattern=
 #=================================================
 
 # Calculate and store the config file checksum into the app settings
-ynh_store_file_checksum "${final_path}/app.db"
+#ynh_store_file_checksum "${final_path}/app.db"
 
 #=================================================
 # INTEGRATE SERVICE IN YUNOHOST
diff --git a/scripts/upgrade b/scripts/upgrade
index de73656..cdf1537 100755
--- a/scripts/upgrade
+++ b/scripts/upgrade
@@ -10,7 +10,6 @@ version_gt() {
 # IMPORT GENERIC HELPERS
 #=================================================
 
-source _common.sh
 source /usr/share/yunohost/helpers
 
 #=================================================
@@ -59,13 +58,6 @@ else #on est encore en 0.6.0
 	current_upstream_app_version='0.6.0' 
 fi
 
-#Close unwanted open port in firewall
-if yunohost firewall list | grep -q "\- $port$"
-then
-	ynh_script_progression --message="Closing port $port as it shouldn't be open..."
-	yunohost firewall disallow TCP $port 2>&1
-fi
-
 
 #=================================================
 # BACKUP BEFORE UPGRADE THEN ACTIVE TRAP
@@ -90,12 +82,23 @@ ynh_script_progression --message="Stopping a systemd service..." --weight=2
 ynh_systemd_action --service_name=$app --action="stop"
 
 #=================================================
-# STANDARD UPGRADE STEPS
-#=================================================
-# DOWNLOAD, CHECK AND UNPACK SOURCE
+# ENSURE DOWNWARD COMPATIBILITY
 #=================================================
+ynh_script_progression --message="Downward Compatibility checks..." --weight=1
+#Close unwanted open port in firewall
+if yunohost firewall list | grep -q "\- $port$"
+then
+	ynh_script_progression --message="Closing port $port as it shouldn't be open..."
+	yunohost firewall disallow TCP $port 2>&1
+fi
+
+# If language was set delete it
+if [ ! -z "$language" ]; then
+	ynh_app_setting_delete --app=$app --key=language
+#fi
 
 #binaries version is 0.6.0, we need to go throught upgrade to 0.6.6 so that app.db is correctly updated, otherwise database is corrupted
+#set database settings as per conf file : restart server so that app.db is regenerated, then add new ldap & log settings
 if version_gt "0.6.6" "$current_upstream_app_version" && [ "$current_upstream_package_version" == "0.6.0" ] && [ "$upgrade_type" == "UPGRADE_APP" ]; then
 	ynh_script_progression --message="Upgrading from $current_upstream_app_version to 0.6.6..." --weight=50
 	ynh_setup_source --dest_dir="$final_path" --source_id="app066"
@@ -106,13 +109,28 @@ if version_gt "0.6.6" "$current_upstream_app_version" && [ "$current_upstream_pa
 	#sleep required on low spec like raspberryPi
 	sleep 2s
 	ynh_systemd_action --service_name=$app --action="stop"
+	conf="\"UPDATE settings SET $(. <(echo -E echo $(<../conf/init_calibre_db_settings))), $(. <(echo -E echo $(<../conf/init_calibre_db_ldap_settings))) WHERE ID=1\""
+    eval sqlite3 $final_path/app.db "$conf"
 	current_upstream_app_version="0.6.6"
-	#remove unwanted entry in settings db
 fi
 
+#=================================================
+# STANDARD UPGRADE STEPS
+#=================================================
+# DOWNLOAD, CHECK AND UNPACK SOURCE
+#=================================================
+
+
+
 if [ "$upgrade_type" == "UPGRADE_APP" ]
 then
 	ynh_script_progression --message="Upgrading source files from $current_upstream_app_version to $new_upstream_package_version..." --weight=10
+
+	#Set settings constant initializer of the app
+	ynh_add_config --template="../sources/patches/app-config_sql.py.patch.src" --destination="../sources/patches/app-config_sql.py.patch"
+	ynh_add_config --template="../sources/patches/app-ub.py.patch.src" --destination="../sources/patches/app-ub.py.patch"
+	ynh_add_config --template="../sources/patches/app-constants.py.patch.src" --destination="../sources/patches/app-constants.py.patch"
+	
 	# Download, check integrity, uncompress and patch the source from app.src
 	ynh_setup_source --dest_dir="$final_path"
 fi
@@ -168,37 +186,13 @@ ynh_script_progression --message="Create Multimedia dir..." --weight=1
 ynh_multimedia_build_main_dir
 ynh_multimedia_addaccess $app
 
-#=================================================
-#Update database structure
-#=================================================
-ynh_script_progression --message="Update database..." --weight=1
-### Verify the checksum of a file, stored by `ynh_store_file_checksum` in the install script.
-### And create a backup of this file if the checksum is different. So the file will be backed up if the admin had modified it.
-ynh_backup_if_checksum_is_different "$final_path/app.db"
-
-#set database settings as per conf file : restart server so that app.db is regenerated, then add new ldap & log settings
-if [ "$current_upstream_app_version" == '0.6.6' ]; then
-        ynh_systemd_action --service_name=$app --action="start" --line_match="server on " --log_path="$final_path/calibre-web.log" -t 30
-else
-        ynh_systemd_action --service_name=$app --action="start" --line_match="Starting Gevent server on" -t 30
-fi
-#sleep required on low spec like raspberryPi
-sleep 2s
-#remove unwanted calibre-web.log
-ynh_secure_remove --file="$final_path/calibre-web.log"
-ynh_systemd_action --service_name=$app --action="stop"
-
-conf="\"UPDATE settings SET $(. <(echo -E echo $(<../conf/init_calibre_db_settings))), $(. <(echo -E echo $(<../conf/init_calibre_db_ldap_settings))) WHERE ID=1\""
-eval sqlite3 $final_path/app.db "$conf"
-
 #Update Imagick policy as per https://github.com/janeczku/calibre-web/wiki/FAQ#what-to-do-if-cover-pictures-are-not-extracted-from-pdf-files
+ynh_script_progression --message="Update Imagick policy..." --weight=1
+
 ynh_replace_string --match_string="<policy domain="coder" rights="none" pattern="PDF" />" \
 		--replace_string="<policy domain="coder" rights="read" pattern="PDF" />" \
 		--target_file="/etc/ImageMagick-6/policy.xml"
 
-# Recalculate and store the checksum of the file for the next upgrade.
-ynh_store_file_checksum "$final_path/app.db"
-
 
 #=================================================
 # SETUP LOGROTATE