PDFs don't appear to be updating

If you are using Cloudflare, then most likely Cloudflare could be caching your static data. To force cache busting, edit your nginx.conf file and add in the following snippet

location ~* \.pdf$ {
    add_header Cache-Control no-store;

On Apache based servers, open the /public/.htaccess file and update the mod_headers block

<IfModule mod_headers.c>
    # Blocks Search Engine Indexing
    Header set X-Robots-Tag "noindex, nofollow"

    # Prevents PDF File Caching
    <FilesMatch ".pdf$">
        Header set Cache-Control no-store

Email not sending

If you are experiencing issues sending emails be sure to double check your .env file contains the correct fields configured.

MAIL_FROM_NAME="Full Name With Double Quotes"

If you are using Gmail - Use an app specific password or ensure you have less secure apps turned on.

If you are using Office 365 - You may need to enable SMTP AUTH.

If you are using gmail smtp relay, then a additional .env variable is required.


Emails will fail with the message:

Expected response code 250 but got an empty response

without this additional field.

The MAIL_MAILER field defines which email driver you wish to use, this could be postmark, maildriver, smtp - anything that Laravel 8 supports natively is supported in this app.

If the mail config is correct, the next place to check would be to check the error logs for any errors that are being thrown, the error log is found in storage/logs/laravel.log

The final source of information in diagnosing mail troubles is to inspect the System Logs tab in the dashboard of the application, in here we log any messages from the mail server itself which may be instructive as to the cause of your issues.

If you are using the Queue system ie. QUEUE_CONNECTION=database then you may also want to check the jobs table in the database, there should be no records in that table... If there are records in the table it means that your queue is not running and therefore no mail jobs are being processed.

It's possible the emails are sent but are blocked for DNS, SPF, DKIM or other reasons. In these cases emailing a test invoice to can help debug certain problems.

PDF conversion issues.

We strongly recommend using the built in snappdf package which is a highly performant PDF generator based on the headless chrome/chromium binary. This package is perfect for users that have root access to their server and are able to install the required dependencies if needed.

To configure SnapPDF use the following .env vars


Snappdf is also the default PDF engine in our Docker image, so if you prefer a very simple installation please consider our Docker setup as it is very fast to get going!

If you are on shared hosting, snappdf probably will be impossible for you to use as you do not have access to the subsystem to install the required packages. Instead, you will need to use a hosted PDF service, the two that Invoice Ninja v5 supports is PhantomJS Cloud and our own hosted PDF generator that users with a white label license can use for free to generate unlimited PDFs.

Phantom JS

Phantom JS Cloud is the default PDF engine PhantomJS Cloud to generate your PDFs, the default API key that comes with a clean installation can generate 100 PDFs per day. If you register for an API key, you will be able to generate 500 PDFs per day, which should suit most users.

Phantom JS can be toggled on and off by setting the PHANTOMJS_PDF_GENERATOR to either TRUE or FALSE. The following .env variables are available for configuring PhantomJS.


The PHANTOMJS_SECRET can be any random value, it's used to bypass the client portal password.

Once this has been done you'll need to refresh the config cache:

php artisan optimize

If you experience errors with PDF generation, such as 500 Server error or Failed to load PDF document or a continuous loading bar, try getting a PhantomJS key here, Replace it with the prefilled key a-demo-key-with-low-quota-per-ip-address and run php artisan optimize again.

For PhantomJS to work, your Invoice Ninja installation web address must be public; localhost installations or those on private networks won't be able to use PhantomJS Cloud.

Hosted Invoice Ninja PDF generation

If you are a white label user, then to enable the Invoice Ninja hosted PDF generator you will need to add a variable to the .env file as follows


Don't forget to refresh your cache (not needed for shared hosting!) with php artisan optimize.

Cron not running / Queue not running

It can take up to an hour for the red warning triangle to disappear after correctly configuring your Cron.

After making any changes to your cron setup you'll want to force a recheck of the cron setting. To do this navigate to http://url/update?secret=

If you are faced with your recurring invoices not firing, or your reminders not sending, then most likely your cron job isn't working. The first thing is to make sure you have your cron jobs configured correctly by following the guide here

If you are using shared hosting, then will need to add an additional parameter to the cron command which looks like this:

cd /path/to/root/folder && /usr/bin/php -d register_argc_argv=On artisan schedule:run >> /dev/null 2>&1

This will force a recheck and if the cron is working the red error triangle will disappear.

Platform specific issues

General advice

When facing errors, first set APP_DEBUG=true in .env and execute php artisan optimize to get more extensive debug information.

Erroneous data format for unserializing 'Symfony\Component\Routing\CompiledRoute'

The most common cause of this issue is running multiple version of PHP, if the caches are built with a different version of PHP you may see the above error as differing versions of PHP may not be interoperable on the same installation. Ensure you are running the same CLI and Web PHP version to prevent any errors/

Unable to connect to database after installation

You may need to restart the queue like this

php artisan queue:restart

Nginx: 413 – Request Entity Too Large

This error indicated that the client_max_body_size parameter in NGINX is too small, you will need to edit your nginx config and increase the size

client_max_body_size 100M;

Proxy configuration.

For users that rely on configuring a reverse proxy, please consider this post on our forum which details steps which may assist in configuring a reverse proxy.

Reverse Proxy Invoice Ninja

Problems with migration

If you are experiencing issues with the migration not running as expected please run through the following checklist: not loading for Google

Pdf generation will not working using the inbuilt PDF engine without some subsystem dependencies, please consult this resource for the list of necessary libraries for each supported platform Snappdf required libraries

WebCron configuration

Some systems do not allow cron configurations, one work around is to use a web cron service which can hit a defined endpoint which executes the scheduler via a GET HTTP request. Invoice Ninja has implemented a small service to allow a webcron service to hit the end point:

To configure the service, you need to add a .env variable


Define your own secret password and then re optimize the cache The service will then be activated.

Installing in a subdirectory.

It is possible to install Invoice Ninja in a subdirectory outside the doc root, to enable this you will need to update the .htaccess file (only if you are using the Apache webserver),

RewriteRule ^(.*)$ public/$1 [L]

should be updated to

RewriteRule ^(.*)$ subdirectoryname/public/$1 [L]

Endless setup loop

If you are finding that all your pre setup checks are passing however you keep falling back to the setup screen, this could indicate that you are missing the mysql-client library which is needed to perform the initial migration. If you are unable to install this for some reason (ie. XAMPP) then you'll need to run the migrations manually by entering the following at the command prompt

php artisan migrate:fresh --seed 

flock() expects parameter 1 to be resource, bool given

This error is thrown from deep within PHP and indicates a permissions issue - most likely the public/storage and/or storage/ directory is not writable by the web user, depending on your platform, you'll need to run something like:

sudo chown -R www-data:www-data public/storage


sudo chown -R www-data:www-data storage/

Unresponsive UI

If for some reason the UI becomes unresponsive, you may need to flush some subsystem configuration and rebuild. It is possible to do this by navigating to the /update?secret= route, ie. https://invoiceninja.test/update?secret= This will perform a number of system clean ups and may resolve issues resulting from an incomplete upgrade. To protect this route, you are advised to add a .env pararameter UPDATE_SECRET=a_secret_passcode this will restrict the route to users with the UPDATE_SECRET passcode.

Communication link failure: 1153 Got a packet bigger than 'max_allowed_packet'

If you are using the database for your queue's then sometimes you may see an error from MySQL

1153 Got a packet bigger than 'max_allowed_packet'

This indicates the insertion payload is bigger than MySQL is configured to handle! To work around this, you will need to increate the mysql variable


To a larger value. Sometimes a value of 1024M is required.

It may also be wise to increase the variable


as similar errors can be reported from the DB.

500 error when editing PDF templates

There was a report from the user who solved 500 error on their server by disabling ModSecurity.

Unresolvable dependency resolving [Parameter #0 [ array $options ]] in class App\Utils\CssInlinerPlugin

When changes are made to the container this can causes the cache to become stale in the application preventing it from booting.

The solution is to clear the contents of the folder bootstrap/cache, by either manually deleting files or by running /update?secret= which will also delete the contents of this directory.

Want to contribute? Edit this page on GitHub!