Data2mem fails in Vivado if the path to the BMM file contains a directory named "microblaze"
In the Vivado Design Suite 2014.2, the data2mem bmm parsing code checks for the case-insensitive word microblaze as a predefined keyword and treats it as an application rather than a directory.
In Vivado 2014.2 and earlier, "microblaze" cannot be used as a level of hierarchy.
To work around this issue in Vivado 2014.2 rename your hierarchy from microblaze to my_microblaze, or anything other than just "microblaze".
This issue is fixed in Vivado 2014.3.