Maximum function nesting level

Maximum function nesting level of '100' reached, aborting!

If you are getting this error, it means your PHP is set to load the xdebug extension and that the nesting level is limited to 100.

Using xdebug might be useful for debugging but if you are on a production server or don't even know what xdebug is, we strongly suggest you disable the extension altogether. You will immediately notice an increase in speed after that and the error would not show again.

In case you are using xdebug for debugging and you need the extension enabled, then you should increase the max_nesting_level setting (256 is a good value).

Disabling Xdebug

Edit the php.ini file and search for xdebug. You should find a line that starts with zend_extension= and the path of the xdebug extension getting loaded. Comment that line out by prefixing with a semicolon (;):

;zend_extension="/usr/local/opt/php56-xdebug/xdebug.so"

Then restart your Apache server.

Increasing max_nesting_level value

Edit the php.ini file and search for [xdebug]. You should find a block containing the xdebug extension location and settings.

See if there is already an entry xdebug.max_nesting_level, if not, just add it at the end of the block with a higher value than 100:

[xdebug]
zend_extension="/usr/local/opt/php56-xdebug/xdebug.so"
xdebug.remote_enable=1
xdebug.remote_handler=dbgp
xdebug.remote_port=9000
xdebug.remote_autostart=0
xdebug.remote_connect_back=0
xdebug.var_display_max_depth=6
xdebug.max_nesting_level=256

Then restart your Apache server.