Solution : https://service.sap.com/sap/support/notes/991266 (SAP Service marketplace login required)
Key words : 
create root directory, terms bia installation, solution create, directory creation, directory /sapmnt, bi accelerator, error message, broken reason, installation fails, installation
Related Notes : 
       
| 989952 | BIA 7.00: Revision 29 | 
| 989305 | BIA 7.00: Revision 28 | 
| 987046 | BIA 7.00: Revision 27 | 
| 883726 | BIA 7.00: Central Note SAP NetWeaver BI accelerator | 
| 882756 | Performance Indicators: BW values visible for non-BW systems | 
| 875400 | BIA 7.00/7.20: Install SAPNetWeaver 7.0 BI accelerator |