Issues after installation or update

In this article


Can't install or update Smart Slider, receiving a PCLZIP_ERR_BAD_FORMAT error message.

Another possible error message:  Update failed: Download failed. The checksum of the file (4a3b9...) does not match the expected checksum value (23173...).

Possible causes

You are using a warez/nulled version

If you haven't purchased Smart Slider Pro from us, but it was downloaded from a torrent or other warez/nulled website. In this case your Smart Slider can't and won't have a valid license and you won't be able to update it.

To be able to update Smart Slider you're required to have a license. You can get one by purchasing a plan that suits your needs.

If you downloaded Smart Slider from a warez/nulled website, be sure you perform a security check on your site after removing the warez version as warez plugins often contain malicious codes.

In case you aren't sure, that you have a warez version, check this documentation to do some tests.

Problem happens during installation - Download issue

If you wanted to do an installation, so you downloaded a zip file from our website or with the Free version maybe from,it could be, that when our zip file was downloaded something bad happened, and your download didn't worked, producing a zip file with an error. To make sure your zip file doesn't have an error, just try to unzip it into your computer.

Problem happens during update - License issue

If you are using the Pro version of Smart Slider and your license is not activated on your website, or there is an issue happening which blocks the license connection, then your website won't receive our zip file.

On the Dashboard you should check the Info popup. This writes out "Your license is active" if you have activated the license. If your license is not active, activate it!

If the license is active, go to the Help center. Under "Possible conflicts" you should press the "Test connection" button. This will show you whether or not there is an issue with the connection.

  • If everything seems fine, go to the next possible cause.
  • But if it isn't fine, check out the "Debug information" error log. A common error message you might find is the "certificate has expired" message. If you see that within your log, check out this documentation. But if you do not see that within your log, contact us and send the log from the"Debug information". We will tell you what you should ask from your server host to fix.
Server's Modsecurity

Your server host might uses a Modsecurity rule, which blocks our zip file for some reason. You should contact your server host and ask them to take a look at their logs. They should see when a Modsecurity rule blocks something and they should be able to figure out the exact source of this issue, and they should turn off that Modsecurity rule. If they aren't sure, just ask them to turn off all Modsecurity rules, and take a look, if the PCLZIP_ERR_BAD_FORMAT still happens.

Server's unzipping program is outdated

The last possible cause of this PCLZIP_ERR_BAD_FORMAT error message is, that your server's unzipping program is outdated or it has an error, and it's not able to unzip our zip file.

You should contact your server host to resolve this error.

Alternative solution

You can use the FTP installation/updating method, where you are unzipping the zip file manually, so your server doesn't have to do it:



This won't fix the PCLZIP_ERR_BAD_FORMAT error, but you won't have to deal with it right now.

PHP Fatal error

Common errors:

  • Fatal error: Class 'N2PluginBase' not found
  • Fatal error: Class 'N2CacheImage' not found
  • require_once(): Failed opening required ... Autoloader.php
  • require_once(): Failed opening required [some file].php

The problem is caused by that installing/updating your Smart Slider 3 didn't worked, some of the files are missing probably because of a server issue. A reinstallation (which is the same as the alternative update) would solve the problem!

You can find instructions in these articles on how to perform an alternative update on WordPress and on Joomla.

JavaScript error

You can find common JavaScript errors within this documentation.

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