Updating/upgrading Plesk or accessing menu “System Updates” on server with CentOS/RHEL/CloudLinux 7 fails: /lib64/libcurl.so.4: undefined symbol: nghttp2_session_callbacks_set_error_callback

Symptoms

Note: The article is applicable only to Plesk servers with CentOS/RHEL/CloudLinux 7 operating systems.

• Updating/upgrading Plesk and running the command yum update (or any other yum command) fails:

  Failed to check system configuration - Yum utility finished with errors. Installation may fail.
   Traceback (most recent call last):
   ..........
   ImportError: /lib64/libcurl.so.4: undefined symbol: nghttp2_session_callbacks_set_error_callback

• Opening the Plesk menu Tools & Settings > System Updates fails:

  PLESK_ERROR: Unable to receive update information for the package(s)

• Cannot enable Modsecurity:

  PLESK_ERROR: Error: modsecurity_ctl failed: START httpd_modules_ctl –enable security2,unique_id
  systemd[1]: httpd.service failed.
  ***** problem report *****
  Warning: start service httpd failed

• Apache configuration check shows error:

  # httpd -t
  httpd: Syntax error on line 353 of /etc/httpd/conf/httpd.conf: Syntax error on line 1 of /etc/httpd/conf.d/security2.conf: Cannot load modules/mod_security2.so into server: /usr/lib64/libcurl.so.4: undefined symbol: nghttp2_session_callbacks_set_error_callback

Cause

Corrupted package libnghttp2.

Resolution

1. Find the package libnghttp2 in the EPEL repository at https://dl.fedoraproject.org/pub/epel/7/x86_64/Packages/l/ and copy the link to download it.

2. Connect to the server using SSH.

3. Download and install the package libnghttp2 using the link obtained in step 1:

   # rpm -Uvh https://dl.fedoraproject.org/pub/epel/7/x86_64/Packages/l/libnghttp2-1.31.1-2.el7.x86_64.rpm