Well, actually, the advice there is close, but it doesn't help in this case. The poster there tells you to do this:
Do the following to get rid of the above.
mv /etc/asterisk/sip.conf /etc/asterisk/sip.conf.old
mv /etc/asterisk/iax.conf /etc/asterisk/iax.conf.old
mv /etc/asterisk/extensions.conf /etc/asterisk/extensions.conf.old
mv /var/lib/asterisk/bin/fax-process. pl /var/lib/asterisk/bin/fax-process.pl.old
/var/lib/asterisk/bin/retrieve_conf
Which is fine, except that none of those are the file that FreePBX is complaining about in this case. The principle is the same, but what you really have to do is:
mv /etc/asterisk/features.conf /etc/asterisk/features.conf.old
/var/lib/asterisk/bin/retrieve_conf
When I did that, I got three error messages:
[ERROR] Error code 0: trying to create empty file /etc/asterisk/features_general_custom.conf
[ERROR] Error code 0: trying to create empty file /etc/asterisk/features_applicationmap_custom.conf
[ERROR] Error code 0: trying to create empty file /etc/asterisk/features_featuremap_custom.conf
BUT it created the empty (and probably totally unnecessary) files, and FreePBX didn't give any more ominous warning messages.
However, one thing I did notice, when running /var/lib/asterisk/bin/retrieve_conf, was this message in the output:
Use of uninitialized value in string eq at /var/lib/asterisk/bin/retrieve_op_conf_from_mysql.pl line 415.
Line 415 of that file looks like this:
I'm no perl expert by any means, but I do know that in this line "eq" isn't a string, it's a conditional operator. It's used in the same manner in several of the lines just preceding this line (with no apparent complaints) so I have no idea what's being complained about here - however, this appears to be a section of code that deals with the setup of parking lots, so if parking lots aren't working properly, this just may be the issue.