OK, so presumably you don't have all of the RealTracks installed, or they are installed on a different path.
The "C:\bb\RealTracks\Viola, Background, Pop Ev 085 (1TrackStringSection)" folder should contain this:
Directory of C:\bb\RealTracks\Viola, Background, Pop Ev 085 (1TrackStringSection)\
24-Jan-15 05:55 AM <DIR> .
24-Jan-15 05:55 AM <DIR> ..
28-Nov-13 02:00 PM 288 vla001.bt1
28-Nov-13 02:00 PM 1,764,151 vla001.wma
28-Nov-13 02:00 PM 288 vla002.bt1
28-Nov-13 02:00 PM 1,764,151 vla002.wma
28-Nov-13 02:00 PM 288 vla003.bt1
28-Nov-13 02:00 PM 1,764,151 vla003.wma
28-Nov-13 02:00 PM 288 vla004.bt1
28-Nov-13 02:00 PM 1,764,151 vla004.wma
28-Nov-13 02:00 PM 288 vla005.bt1
28-Nov-13 02:00 PM 1,764,151 vla005.wma
28-Nov-13 02:00 PM 288 vla006.bt1
28-Nov-13 02:00 PM 1,764,151 vla006.wma
28-Nov-13 02:00 PM 288 vla007.bt1
28-Nov-13 02:00 PM 1,764,151 vla007.wma
28-Nov-13 02:00 PM 288 vla008.bt1
28-Nov-13 02:00 PM 1,764,151 vla008.wma
28-Nov-13 02:00 PM 288 vla009.bt1
28-Nov-13 02:00 PM 1,764,151 vla009.wma
28-Nov-13 02:00 PM 288 vla010.bt1
28-Nov-13 02:00 PM 1,764,151 vla010.wma
28-Nov-13 02:00 PM 288 vla011.bt1
28-Nov-13 02:00 PM 1,764,151 vla011.wma
28-Nov-13 02:00 PM 288 vla012.bt1
28-Nov-13 02:00 PM 1,764,151 vla012.wma
28-Nov-13 02:00 PM 288 vla013.bt1
28-Nov-13 02:00 PM 1,764,151 vla013.wma
28-Nov-13 02:00 PM 288 vla014.bt1
28-Nov-13 02:00 PM 1,764,151 vla014.wma
28-Nov-13 02:00 PM 288 vla015.bt1
28-Nov-13 02:00 PM 1,764,151 vla015.wma
28-Nov-13 02:00 PM 288 vla016.bt1
28-Nov-13 02:00 PM 1,764,151 vla016.wma
28-Nov-13 02:00 PM 288 vla017.bt1
28-Nov-13 02:00 PM 1,764,151 vla017.wma
28-Nov-13 02:00 PM 288 vla018.bt1
28-Nov-13 02:00 PM 1,764,151 vla018.wma
01-Oct-14 07:00 AM 288 vla031.bt1
01-Oct-14 07:00 AM 1,363,954 vla031.wma
01-Oct-14 07:00 AM 288 vla032.bt1
01-Oct-14 07:00 AM 1,366,215 vla032.wma
01-Oct-14 07:00 AM 288 vla033.bt1
01-Oct-14 07:00 AM 1,363,954 vla033.wma
01-Oct-14 07:00 AM 288 vla034.bt1
01-Oct-14 07:00 AM 1,363,954 vla034.wma
01-Oct-14 07:00 AM 288 vla035.bt1
01-Oct-14 07:00 AM 1,366,215 vla035.wma
01-Oct-14 07:00 AM 288 vla036.bt1
01-Oct-14 07:00 AM 1,791,283 vla036.wma
01-Oct-14 07:00 AM 288 vla037.bt1
01-Oct-14 07:00 AM 1,789,022 vla037.wma
01-Oct-14 07:00 AM 288 vla038.bt1
01-Oct-14 07:00 AM 1,791,283 vla038.wma
01-Oct-14 07:00 AM 288 vla039.bt1
01-Oct-14 07:00 AM 1,789,022 vla039.wma
01-Oct-14 07:00 AM 288 vla040.bt1
01-Oct-14 07:00 AM 1,789,022 vla040.wma
01-Oct-14 07:00 AM 288 vla041.bt1
01-Oct-14 07:00 AM 1,737,019 vla041.wma
01-Oct-14 07:00 AM 288 vla042.bt1
01-Oct-14 07:00 AM 1,737,019 vla042.wma
01-Oct-14 07:00 AM 288 vla043.bt1
01-Oct-14 07:00 AM 1,737,019 vla043.wma
01-Oct-14 07:00 AM 288 vla044.bt1
01-Oct-14 07:00 AM 1,737,019 vla044.wma
01-Oct-14 07:00 AM 288 vla045.bt1
01-Oct-14 07:00 AM 1,737,019 vla045.wma
01-Oct-14 07:00 AM 288 vla046.bt1
01-Oct-14 07:00 AM 1,366,215 vla046.wma
01-Oct-14 07:00 AM 288 vla047.bt1
01-Oct-14 07:00 AM 1,366,215 vla047.wma
01-Oct-14 07:00 AM 288 vla048.bt1
01-Oct-14 07:00 AM 1,366,215 vla048.wma
01-Oct-14 07:00 AM 288 vla049.bt1
01-Oct-14 07:00 AM 1,366,215 vla049.wma
01-Oct-14 07:00 AM 288 vla050.bt1
01-Oct-14 07:00 AM 1,366,215 vla050.wma
76 File(s) 63,055,756 bytes
2 Dir(s) 306,039,451,648 bytes freeGo to Options > Preferences > RealTracks and check what folder is used for your RealTracks settings location. If that points elsewhere, you may not have all of the RealTracks installed at that location?