Warning messages after when updating plugin

Hi,

What kind of hosting do you have? It does not seem to support exclusive locks, hence the first warning (line 184):

$tmp = file_put_contents( $nfdbhash, md5( serialize( $adm_users) ), LOCK_EX );

Note that adding a ‘@’ at the beginning of ‘file_put_contents’ should prevent any warning:

$tmp = @file_put_contents( $nfdbhash, md5( serialize( $adm_users) ), LOCK_EX );

I don’t understand too much the last 2 errors referring to lines 366 and 367, because the /ninjafirewall/lib/nfw_misc.php script has only 250 lines.

It is not too much important, your file system does not support exclusive locks, and the shared one (LOCK_SH) isn’t really useful.
I will make some changes to the next version in order to get rid of the warning message.

The firewall will keep working as usual.
Exclusive locks are used to prevent race condition: when an application writes to a file, it locks it so that no other instance of that application (or another app) can write to it at the same time.