Akeeba Backup for Joomla! displays AJAX Error, 500 Internal Server Error or the backup does not complete

If the backup process does not start, i.e. you click on the button and nothing happens, please go through the client-side troubleshooting steps before doing anything else. Most likely it's an issue with your PC configuration or ISP.

Before you do anything else, make sure that your server complies with the minimum requirements of Akeeba Backup. The PHP and Joomla! version compatibility matrix is published on our site.


If you have tried all of the above and your site is hosted on, check out the special instructions at the bottom of this page.

The most usual backup issues manifest themselves by means of an "AJAX Loading Error" message. This error message by itself means pretty much nothing. All it tells us is that the backup failed. Normally, you should post your log file to our ticket system so that we can take a look at it to figure out what went wrong. However, there are some common issues you can work around yourself, without looking at the log file. You should follow the following troubleshooting steps one by one until your backup works.

  1. Are you on Windows, backing up a local site? Some antivirus and backup software may end up locking the backup archive while it's still being created, leading to an error message about the backup archive not being able to be opened for writing. One very notorious case of this kind is WD SmartWare backup software (kudos to our user, Markus, for letting us know). We strongly advise you to turn off or at least temporarily suspend any backup and antivirus software while the backup is in progress.

    Another issue on Windows is resource usage, especially on old (Windows XP) and 32-bit versions of Windows. These versions of Windows have a limited capacity of system resources, meaning that they can only keep a very finite number of files open at any time. Combined with a bug in older versions of PHP for Windows this can lead to resource depletion and backup issues, appearing as unreadable files. Please try quitting as many applications as possible, including those running in the background (e.g. those running as system tray icons). It's also a good idea to turn off or temporarily suspend resource-intensive software such as backup and antivirus applications while the backup is running.

  2. Sometimes the backup seems to complete, but it hangs when uploading the backup archive to a remote location (e.g. Dropbox, Amazon S3, an FTP server, ...). If you are not sure, the hang we're describing happens after the progress bar hits 75%. In this case you will need to lower the Part Size for Split Archives setting. Find the Archiver Engine option of the Akeeba Backup's Configuration page and click on the Configure... button next to it. The Part Size for Split Archives setting is in the pane which opens below. Try smaller settings until the backup completes. Please note that your backup will now be split in multiple files and you need all of them to be present to restore your backup. The exact reason this may be required is described in Akeeba Backup User's Guide, under the cloud backup section.

  3. The first thing you must do is to use the Configuration Wizard button in the Control Panel page to automatically adjust a series of configuration parameters to safer settings. The wizard performs benchmarking of your server to determine those values. It is not always 100% accurate, but the settings it creates are at the very least a good starting point for tweaking them manually. If it seems to get stuck for more than three minutes (180 seconds) the first time you run it, reload the page.

  4. Make sure that your hosts PHP memory_limit is at least 24Mb. Anything lower than that will most likely result to a backup failure. If unsure, ask your host; we can't know this value for sure. If this is an option, ask your host to increase the PHP memory limit. We recommend 64Mb for medium-sized sites, 128Mb for larger sites.

  5. Try visiting the Configuration page and clicking on Save. This may be necessary if you just upgraded. This simple move will refresh your configuration and pick up the default values for any new parameters which might have been introduced in the new release.

  6. Check your free space. Akeeba Backup is trying to create an archive with your entire database and all of your site's files; it needs adequate free space to do that. If you don't have enough free space, your host will kill the script in mid-process, making Akeeba Backup's interface throw this error. As a rule of thumb, we propose having about 40-50% of your account's allocated quota free.

    Some hosts claim to give you "unlimited" space, or an absurd amount like 100Gb. According to our experience, they mostly lie. On many occasions the host only gave 100Mb or 1Gb of space. If unsure, please ask your host about the real free space you have in your account.

  7. Which temporary directory are you using? If you are using the system wide temporary directory or your account's default temporary directory you might run into problems. Most host periodically clear these contents of these directories to ensure that their server doesn't run out of free space. If in doubt, you can always work around this easily. Go to Akeeba Backup's Configuration page. Find the Temporary directory setting and set it to [DEFAULT_OUTPUT] (including the brackets!). Click on Save and retry backup.

  8. If you are using the ZIP archive format it is possible that you run into timeouts. The problem with the ZIP format is that we have to read each file twice. We read it once in order to calculate a "file signature" (properly called a "CRC32 checksum"), then we read it again in order to add it inside the archive. Unfortunately these steps can't be combined and, on top of that, the very slow signature calculation step must be able to run in one go. With larger files and slower hosts this will consistently lead to timeouts. If you suspect this is the case, please use the JPA format setting in the Archiver Engine option of the Akeeba Backup's Configuration page.

    Note: On some hosts you might have to use the "ZIP Format" or "ZIP using ZipArchiver" options instead of JPA.

  9. Some servers have a very strict limit on the maximum execution time of PHP scripts. By default, Akeeba Backup is configured with a maximum execution time allowance of 14 seconds. In order to work around such hosts, please go to your Akeeba Backup Configuration page and scroll all the way down to the Fine Tuning pane. You will find an option labeled Maximum Execution Time. Select the "Custom..." option and type in 5 in the text box that appears to the right of the drop-down. Click on the Save button and retry backing up your site. WARNING! NEVER SET THE Minimum execution time TO A VALUE HIGHER THAN 2 SECONDS UNLESS EXPLICITLY ASKED TO DO SO BY THE SUPPORT STAFF, OR YOU WILL GET A BACKUP FAILURE.

    We have heard of hosts which require settings even lower than that. If in doubt, ask your host what their PHP maximum_exec_time setting is, then subtract one second and use this value in Akeeba Backup's Maximum Execution Time setting.

If you still have issues, please continue to "Any other Akeeba Backup related question" page for further instructions on reporting your problem. For your convenience, please make sure you indicate that you have gone through the steps on this page when posting your support request to avoid a canned reply that you should check this page first. Thank you.

Special notes for customers

If your site is hosted on please follow these instructions if the above doesn't work:

  1. Run the Configuration Wizard but do not take a backup yet

  2. Go to Akeeba Backup's Configuration page and set the following parameters:

    • Logging Level: Only errors (however, if you want to ask for support in our ticket system you must switch it back to All Information and Debug and try taking a new backup before posting us your log file)

    • Click the Configure button in the Archiver Engine and set the "Part size for split archives" to 127Mb or less.

    • Minimum execution time: 10 seconds

    • Maximum execution time: 7 seconds

    • Execution time bias: 50%

Please note that the above settings do cause the backup to run at half speed, but this is required for your backup to run under smoothly on We'd like to thank's tech support for testing and providing these safe settings.