I'm using the bass VST from Studio Instruments (amazing value for money BTW) and I've found that when I import midi from Guitar Pro it has notes that are below the range of the instrument. Notes in the lower part of octave 1 (I think, the range that starts with C1 in the midi editor in Reaper) are just silent. Steinberg's free bass VB-1 handles that fine...

Any ideas on how best to approach this? Transpose the silent notes into the next octave, or transpose all of it? Is there a tool or function (preferrably in Reaper) to do this?

Solved it myself, the problem is that Reaper imports the midi one octave too low. Don't know if the problem is Reaper och Guitar Pro, doesn't matter.