Apache fails to start on Plesk server: undefined symbol: ap_unixd_setup_child

[Suhitha]

Question: Apache fails to start on Plesk server: undefined symbol: ap_unixd_setup_child


Applicable to:

• Plesk Onyx for Linux[

/b]


Symptoms

• The following error occurs on attempt to start Apache web server:

httpd: Syntax error on line 353 of /etc/httpd/conf/httpd.conf: Syntax error on line 6 of /etc/httpd/conf.d/fcgid.conf: Cannot load modules/mod_fcgid.so into server: /etc/httpd/modules/mod_fcgid.so: undefined symbol: ap_unixd_setup_child

• After disabling mod_fcgid Apache fails with:

AH00526: Syntax error on line 66 of /etc/httpd/conf/httpd.conf:
Invalid command 'User', perhaps misspelled or defined by a module not included in the server configuration


Cause

The mod_unixd module is disabled on the server.


Resolution

It is required to enable mod_unixd in order to fix this issue.

1.Log into Plesk

2.Go to Tools & Settings > Apache Web Server

3.Select the mod_unixd module

4.Click OK

5.Go to Tools & Settings > Service Management and start the Apache Web Server service

Note: enable mod_fcgid back in case it was disabled during the troubleshooting.


Additional information

See the following article for the command line resolution: After dist-upgrade Apache was upgraded from 2.2 to 2.4, Apache and cannot start