PRODUCT: Plesk 9.5.4 on Centos 5.4 x86_64 Trying to update through GUI. On my other (identical) servers no problem. But this one particular server keeps saying: Unable to obtain the latest version of Parallels Products Installer: The required version '3.11.0' was not found on the server. This could happen because of configuration error at the download site. Failed to open the file /var/cache/parallels_installer/parallels_installer_CentOS_5_x86_64 for writing: Text file busy. Does anyone have had this problem? Any solution?