SnappyMail Version 2.28.1 - Unable To Access Webmail After CyberPanel Upgrade

[thatcher]

Hello everyone!
After the latest CyberPanel update, which updated SnappyMail, email (sending/receiving) works using IMAP access, however, SnappyMail fails to load (error log below).

OS Info: Ubuntu 20.04.6 LTS

CyberPanel Version Info:

Current Version: 2.3
Build: 4
Current Commit: f337f895514e0f9eb5240976e09f18cca161cc14
Latest Version: 2.3
Latest Build: 4
Latest Commit: f337f895514e0f9eb5240976e09f18cca161cc14

Steps To Reproduce:
Whilst accessing webmail via: https://SERVER_IP:8090/snappymail

Error Produced (Image):

Error Produced (Raw Text):

An error occurred.
Please refresh the page and try again.
SyntaxError: Unexpected token '<', "<br /> <b>"... is not valid JSON

Warning: pcntl_async_signals() has been disabled for security reasons in /usr/local/CyberCP/public/snappymail/snappymail/v/2.28.1/app/libraries/MailSo/Log/Logger.php on line 76
Warning: pcntl_signal() has been disabled for security reasons in /usr/local/CyberCP/public/snappymail/snappymail/v/2.28.1/app/libraries/MailSo/Log/Logger.php on line 78

Warning: Cannot modify header information - headers already sent by (output started at /usr/local/CyberCP/public/snappymail/snappymail/v/2.28.1/app/libraries/MailSo/Log/Logger.php:78) in /usr/local/CyberCP/public/snappymail/snappymail/v/2.28.1/app/libraries/snappymail/http/csp.php on line 79

Warning: Cannot modify header information - headers already sent by (output started at /usr/local/CyberCP/public/snappymail/snappymail/v/2.28.1/app/libraries/MailSo/Log/Logger.php:78) in /usr/local/CyberCP/public/snappymail/snappymail/v/2.28.1/app/libraries/snappymail/http/csp.php on line 82

Warning: Cannot modify header information - headers already sent by (output started at /usr/local/CyberCP/public/snappymail/snappymail/v/2.28.1/app/libraries/MailSo/Log/Logger.php:78) in /usr/local/CyberCP/public/snappymail/snappymail/v/2.28.1/app/libraries/RainLoop/Service.php on line 38

Warning: Cannot modify header information - headers already sent by (output started at /usr/local/CyberCP/public/snappymail/snappymail/v/2.28.1/app/libraries/MailSo/Log/Logger.php:78) in /usr/local/CyberCP/public/snappymail/snappymail/v/2.28.1/app/libraries/MailSo/Base/Http.php on line 188

Warning: Cannot modify header information - headers already sent by (output started at /usr/local/CyberCP/public/snappymail/snappymail/v/2.28.1/app/libraries/MailSo/Log/Logger.php:78) in /usr/local/CyberCP/public/snappymail/snappymail/v/2.28.1/app/libraries/MailSo/Base/Http.php on line 189

Warning: Cannot modify header information - headers already sent by (output started at /usr/local/CyberCP/public/snappymail/snappymail/v/2.28.1/app/libraries/MailSo/Log/Logger.php:78) in /usr/local/CyberCP/public/snappymail/snappymail/v/2.28.1/app/libraries/MailSo/Base/Http.php on line 190

Warning: Cannot modify header information - headers already sent by (output started at /usr/local/CyberCP/public/snappymail/snappymail/v/2.28.1/app/libraries/MailSo/Log/Logger.php:78) in /usr/local/CyberCP/public/snappymail/snappymail/v/2.28.1/app/libraries/MailSo/Base/Http.php on line 191

Warning: Cannot modify header information - headers already sent by (output started at /usr/local/CyberCP/public/snappymail/snappymail/v/2.28.1/app/libraries/MailSo/Log/Logger.php:78) in /usr/local/CyberCP/public/snappymail/snappymail/v/2.28.1/app/libraries/RainLoop/Service.php on line 152

Warning: Cannot modify header information - headers already sent by (output started at /usr/local/CyberCP/public/snappymail/snappymail/v/2.28.1/app/libraries/MailSo/Log/Logger.php:78) in /usr/local/CyberCP/public/snappymail/snappymail/v/2.28.1/app/libraries/snappymail/http/csp.php on line 79

Warning: Cannot modify header information - headers already sent by (output started at /usr/local/CyberCP/public/snappymail/snappymail/v/2.28.1/app/libraries/MailSo/Log/Logger.php:78) in /usr/local/CyberCP/public/snappymail/snappymail/v/2.28.1/app/libraries/snappymail/http/csp.php on line 82

Please advise.

Thanks

[thatcher]

This community is (almost) dead. Nobody cares I guess. It’s been like 20 days…
Anyways, I fixed it myself.

[SOLUTION]

• Login to your Cyberpanel instance
• Go to PHP → Edit PHP Configs → Advanced
• Select your default Cyberpanel PHP version (whichever it may be, in my case, 7.4)
• Scroll down to the section disable_functions =
• Find and delete the following 2 PHP Functions from the list:
  • pcnt_signal
  • pcntl_async_signals
• Click Save Changes
• Voila.

Note: If it still doesn’t work, reboot your Linux server, and it should definitely work.