diff --git a/dependencies/user-install.sh b/dependencies/user-install.sh
index 4cfe2b3..594f8e2 100755
--- a/dependencies/user-install.sh
+++ b/dependencies/user-install.sh
@@ -108,6 +108,7 @@ Description=Running and monitoring contract fs.
 StartLimitIntervalSec=0
 [Service]
 Type=simple
+ExecStartPre=/bin/bash -c '( ! /bin/grep -qs $user_dir/$contract_dir/contract_fs/mnt /proc/mounts ) || /bin/fusermount -u $user_dir/$contract_dir/contract_fs/mnt'
 EnvironmentFile=-$user_dir/.serviceconf
 ExecStart=/bin/bash -c '$script_dir/hpfs fs -f $user_dir/$contract_dir/contract_fs -m $user_dir/$contract_dir/contract_fs/mnt -u $contract_host_uid:$contract_host_gid -t \${HPFS_TRACE}\$([ \$HPFS_MERGE = \"true\" ] && echo \" -g\")'
 Restart=on-failure
@@ -120,6 +121,7 @@ Description=Running and monitoring ledger fs.
 StartLimitIntervalSec=0
 [Service]
 Type=simple
+ExecStartPre=/bin/bash -c '( ! /bin/grep -qs $user_dir/$contract_dir/ledger_fs/mnt /proc/mounts ) || /bin/fusermount -u $user_dir/$contract_dir/ledger_fs/mnt'
 EnvironmentFile=-$user_dir/.serviceconf
 ExecStart=$script_dir/hpfs fs -f $user_dir/$contract_dir/ledger_fs -m $user_dir/$contract_dir/ledger_fs/mnt -t \${HPFS_TRACE} -g
 Restart=on-failure
diff --git a/examples/message-board/message-board.js b/examples/message-board/message-board.js
index d85e9c0..fd14b43 100644
--- a/examples/message-board/message-board.js
+++ b/examples/message-board/message-board.js
@@ -260,7 +260,7 @@ const interatctiveInterface = async () => {
                             owner_pubkey: 'ed5cb83404120ac759609819591ef839b7d222c84f1f08b3012f490586159d2b50',
                             contract_id: contractId,
                             image: (image == "1" ? "hp.latest-ubt.20.04" : "hp.latest-ubt.20.04-njs.14"),
-                            config: ret !== -1 ? createConfig : undefined
+                            config: ret !== -1 ? createConfig : {}
                         }));
                         break;
                     // case 'initiate':