Can anyone make sense of this:

[00:00:04.2450000] Error: Input file 'data:common/baseambientstream.xml' not found (referenced from file://c:\program files\electronic arts\ra3 mod sdk\mods\my upheaval\data\specific\ambientstream.xml). Treating it as empty.

[00:00:04.2780000] Critical: Instance AmbientStream:AmbStream_FloatingFortress_Quad [ea2c2798:18c6d517] attempts to inherit from or override non-existing instance AmbientStream:BaseAmbientStream [ea2c2798:1f94056b]
Build failed on step 2

?

My first real time trying to make a RA3 mod, just a little personal edit to RA3 upheavel (using Bibber's generous source code) but it just keeps giving me this dang error.