If you have a cpanel server and you've a problem with your crontab permission are wrong please set to 4755.

Please kindly to follow up this step below to solved your crontab permission issue.

Anyway, if you get the message:
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/usr/bin/crontab permissions are wrong. Please set to 4755

You can fix it by logging in via ssh/root and giving it some:
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$chmod 4755 /usr/bin/crontab

There is an error in Cpanel hosting server that cause Add-on domain is not working properly.

Here is a various symptoms:
* When user adding add-on domain and delete it and then re-adding it again, it will show error
* Or if the domain to be added was a single user account on the same server (even after being terminated) it cant be added
* Add-on just disappear after CPANEL update

The fastest solution is :
Login into your Cpanel server with root access.

What is IonCube ?

Secure and license your PHP scripts with the ionCube PHP Encoder. Protect files with PHP encoding, encryption, obfuscation and licensing capabilities.

Prepare Webserver and PHP
I assume you already have apache webserver and php installed on your server.

Download IonCube and Install it :

Here is the simple steps How To Update Cpanel From Release to Stable Version.

Login into your server with root access

Don't forget to running Cpanel Update again with this command line below :
$/scripts/upcp --force

If you need to upgrade your cPanel to the latest version.
Run script below and wait few time untill process done.
/scripts/upcp --force

After done, you must reboot your server to make it working properly.
shutdown -r now

In cPanel server, if you go to Software -> Module Installer



Then on PHP Pecl, click on Manage

Then click on Show Available PHP Pecl(s) button

If you got error like picture below, "There was a problem fetching the module list.",