Unable to upgrade Plesk: /usr/local/lib/libcurl.so.4: no version information available

Symptoms

• Unable to upgrade Plesk, the process fails with the error:

  Web server configuration is broken. We will try to repair it. This operation can take a lot of time, please do not interrupt the process.
  /usr/bin/sw-engine: /usr/local/lib/libcurl.so.4: no version information available (required by  /usr/bin/sw-engine)

• The execution of the plesk login command fails with the same error message.

• The Plesk GUI can be inaccessible with the following error message:

  PHP Warning: Unknown: failed to open stream: No such file or directory in Unknown on line 0
  PHP Fatal error: Unknown: Failed opening required 'auth.php' (include_path='/opt/psa/admin/plib') in Unknown on line 0

Cause

Multiple versions of libcurl are installed on the server and Plesk is using the incorrect version.

Resolution

1. Log into the server via SSH.

2. Excute the command below to remove the symlink for incorrect libcurl version( that is specified in the error):

   # unlink /usr/local/lib/libcurl.so.4