SymptomsI cannot connect to a Parallels Plesk Panel (PP) 8 server via the Parallels Plesk Expand (PPE) control panel.
When trying to log in, I receive the following error:
Cannot open Plesk Server window because Plesk API RPC is not installed on the Plesk Server. Contact your system administrator for support.
While trying to diagnose the problem, I delete the server from PPE, and when trying to add it back, I get the following error:
The specified Plesk server has no PSA API software installed or the installed software is outdated. Please refer to your Plesk Installation Manual to learn how to install/upgrade your PSA API software.
The psa-api-rpc package is installed on the server, so the above error messages are not accurate:
# rpm -qa psa-api-rpc
CauseThe installation of the psa-api-rpc package is probably missing the agent.php file. You may check whether this is the case by using this command, e.g.:
# rpm -V psa-api-rpc-8.6.0-rhel4.build86080930.03
The file may have been deleted in order to eliminate a vulnerability in PP; however, this is not a recommended solution. It is necessary to install Micro-Updates in order to properly protect the server from vulnerabilities.
ResolutionIn order to fix the psa-api-rpc package and install all Micro-Updates, the following steps should be executed on the server where PP is installed:
1) Download the appropriate psa-api-rpc package for PP 8.6 for Windows, depending on your OS/architecture, here:
Example link for RHEL 4 32-bit: