I have 2014 BIAB installed plus sampletank 2.5.
Sampletank is authorized and I can hear sounds from it when running in stand alone mode.
All the audio files are in the C:\programfiles(x86)\IKmultimedia\Sampletank 2.5\Band In a Box sub-directory where they are supposed to be.

In BIAB selecting Hi-Q menu choice from mixer pop-up- BIAB will report files as missing:

for example a drum part:

Hi-Q 001 01 Drums, Acoustic, Rock Kit SampleTank.tgs ** not found in C:\Program Files (x86)\IK Multimedia\SampleTank 2.5\Instruments\Band-in-a-Box\

or strings:

Hi-Q 050 01 Strings, Ensemble, Movie SampleTank.tgs ** not found in C:\Program Files (x86)\IK Multimedia\SampleTank 2.5\Instruments\Band-in-a-Box\

Thanks,
Tom