Some VSTs (Massive, Sylenth1 and probably others) have erratic Automation behaviour when using MIDI hardware to control them
Noticed a problem on my PC with using MIDI CC to control automation. First noticed it in 4.5 rc7 x64 but it also exists in 4.402 x64. If Touch or Latch is selected, turning the MIDI controller knob or slider results in the values to jump all over the place making recording the correct values impossible. If Write mode is used, it behaves correctly as expected and is super smooth when the slider or knob is moved. See the behaviour in the attached licecap (Licecap is only recorded at 5fps, but still should give you the general idea what is happening). In All 3 modes in the licecap (Touch, Latch and Write), I smoothly move the slider on my MPK49 up to the top and back to the bottom once. The licecap shows it jumping all over the place in Latch and Touch modes.
Steps to reproduce:
1. Create new track in Reaper
2. Add Massive VST to track and put track in record arm mode
3. In the Macro Control section of Massive, right click on the 2nd dial and choose MIDI Learn.
4. Move a knob or slider on your keyboard or MIDI device. Test moving the knob or slider and check it turns the dial in Massive.
5. Turn on automation for Massive Dial 2 on the track in Reaper (Make Visible and Arm).
6. Set Touch or Latch automation and move slider or knob to see values jumping all over the place. Turn on Write automation and see it move very smooth and precise.
My config:
Windows 8 Pro 64-bit
Reaper 4.5 rc12 64-bit (problem also happens in 4.402 x64)
SWS Extensions 2.3.0 #19 64-bit (also happens with no SWS installed)
NI Massive 1.3.1 (R129) 64-bit (Latest version)
AKAI MPK49 Keyboard (Firmware 2.04)