You might face this error when restoring a SQL Server Analysis Services cube from a backup.
The following system error occurred: The file exists. . (Microsoft SQL Server 2005 Analysis Services)
The reason the restore process failed is probably because you are trying to restore from a higher version of SSAS to a lower version(example, from SSAS 2012 to SSAS 2008 etc.), which is not supported. Please be sure that you are not going backwards(in version). This holds true for Relational database backups as well.