REPLACE this with (or if it does not exist simply add the below)

define('WP_DEBUG', true);
define('WP_DEBUG_LOG', true);
define('WP_DEBUG_DISPLAY', false);/*this should NEVER be true for production sites*/

Note: this MUST be before /* That's all, stop editing! Happy blogging. */

Which will generate a file “wp-content/debug.log” if and when any errors are encountered.
Check this file for errors if you need to find out where things might go wrong

View the Help Screen

Note that in many cases a lot more information/help is available in the help screens of the plugin

View your browsers console (Typically by using Ctrl+Shift+I)

If you see some “500 Internal server errors” in there, check your server error log. In many cases these are caused by uploading a plugin with the wrong permissions – especially if you add plugins by ftp instead of using the standard wordpress plugin installer. You should also aim to fix any other javascript errors you may have, although some might be more problematic than others

General Troubleshooting

If you have issues with WPPizza – or WordPress in general for that matter – I would highly recommend the following resource(s) to narrow down where your issue(s) might be

As I could not say this any better, forgive me for simply providing the links above. I would, however, especially recommend the “Troubleshooting Plugins” section on the perishablepress.com link ; about 2 thirds down on that page.

Of course, if you have followed the recommendations on those pages without being able to solve your problem and still have issues with WPPizza, please get in touch via the usual channels (forum, contact form, emails)

Warning: session_start(): Cannot start session when headers already sent in [site-path]/wp-content/plugins/wppizza[xyz]/[some-file] on line [some-line]
or
Warning: cannot modify header information - headers already sent by [site-path]/[some-dicetory]/[some-file] on line [some-line]

The problem is that either:

• – php notices/warnings/errors etc are output to the site instead of being logged
• – another plugin – or your theme/child theme – is outputting content where it should not.

Although the session start warning references a wppizza file, this is *not* in fact a wppizza error/fault (as confusing as this might seem, admittedly) but it points to some other file or plugin outputting content before it should do.
If it’s a “cannot modify header information – headers already sent by” instead, it typically also tells some file and line number.

First of all

:

• – make sure you do not output any warnings etc by setting your debug like so or even disabling debug altogether if that’s acceptable in your scenario (wppizza does it’s best to ignore those, but has no influence over other plugins of course)
• – once you have done so, check your site again (clear you browser cache) as this might be all you need to do to make it all work again. Fix other error/notices/warnings at your leaisure

Then – if you are still having session related issues

:

• – disable all other *non*-wppizza plugins and switch to a wordpress default theme (twenty-xyz) , at least temporarily.
• – assuming disabling everything non-wppizza related solves the issue, re-enable your plugins/themes one by one, until it does not work again (so you know what is causing it)
• – fix the issue following the suggestions/guide/answer here or better still, contact the theme/plugin author to fix it.
• – in the event that the above does still not solve your problem, contact me , making sure to send me relevant info (debug.log, url , version numbers etc ) via the usual channels (contact/email/forums)

PS | FYI: Wppizza uses native php sessions – extensively – that simply will not work if other scripts/plugins/themes output content where they should not.

To do so go to: WP(WordPress) -> Settings -> General and enable Anyone can register

If you are using a multisite setup you will have to do this in the network settings:
WP(WordPress) Network settings -> Registration Settings -> Allow new registrations : User accounts may be registered

Furthermore, please ensure the dedicated "email" field in Wppizza -> Order Form Settings is enabled and set to be required (to allow the user to receive his/her password for a newly created account)
This is the field that has the hardcoded, non-changeable “Type / Validation” of “email”

Note: the “continue as guest / register” options will only show up if the user is NOT logged in already (for obvious reasons), else a simple checkbox that allows to “update my details” will be displayed.

In 99.99% of cases this is due to the session save path (php.ini) not being set correctly or at all and/or the directory not existing or not being writable.

Typically this would read
session.save_path = "/tmp"
or
session.save_path = "/var/lib/php5"
or
session.save_path = "/var/lib/php5/session"
or similar in your php.ini.

Refer to the php manual for more details regarding session setup

You should speak to your host / server administrator to get this fixed and to make sure the appropriate path is set with the correct permissions. WPPizza will not work without php session support.

WPPizza requires mySql 5.5+ – (see requirements: https://wordpress.org/plugins/wppizza/ – In fact, WordPress itself recommends 5.6+ )

If the above is the case, update your version of mySql or get your host to update it for you. Once you have done so go to "Wppizza -> Tools -> Maintenance [Tab]" enable/check "Update order table" and save once.

To enable, either add this line to the functions.php of your theme;
add_filter('widget_text', 'do_shortcode');,

use one of the wordpress plugins available that do this

or contact the theme developer and ask him/her to enable it

To fix this, do the following:

• add a new – dummy – category
• drag drop that new category above/below another category
• delete that dummy category again
• reload the page

it should all now show up again as it should and any new php notices to that effect should disappear

For a possible solution have a look at
https://techubber.blogspot.com/2017/09/how-to-fix-wordpress-plugin-update-failed-solutions.html
and generally
https://www.google.com/search?q=Update+Failed%3A+Plugin+update+failed
of course.

Some security plugins will also apply settings that would stop this process to work.
Therefore, if you are using plugins like wordfence or similar, or things like “System Tweaks” in iThemes, try de-activating those (temporarily) and see if the update works then.
(If it does, simply re-activate the aforementioned plugins/settings after your successful update)

If you are using settings in an .htaccess file to restrict siteaccess by implementing some sort of authentication to access your site, disable this authentication requirement then try to update the plugin(s) and subsequently re-enable authentication as appropriate.

If none of that helps, you can also do the following:

(It is always advisable to make a full backup of your site first if things should go wrong for some reason !)

• De-activate the plugin(s) in question but DO NOT UNINSTALL them (if you uninstall, you WILL loose your settings related to the plugin you uninstalled)
• Download the updated/latest versions of the plugin(s) from https://www.wp-pizza.com/my-account/
• Unzip the downloaded update(s) somewhere
• Ftp into your site and simply overwrite the plugin files with the updated ones you unzipped earlier(typically found in [path]/wp-contents/plugins/[plugin-in-question]/[files|dirs to overwrite])
• Note: if you do that you *might* change file permissions/ownership and subsequently get the (same) issue you are having regarding updates – then again as you are using ftp because you already have that issue, it wont change anything really)
• Re-activate the plugin(s) from within the WP dashboard – it will update what needs to be updated

make sure your theme (or one of your plugins) does not use an old version of jQuery (some themes/plugins override the version that comes bundled with wordpress – no, i don’t know either why they would do that)

If that still doesn’t help, you might have to adjust the CSS (see Modify Css)

If you have problems, send me a link to your site I’ll have a look…