The error about mcLua.mcc - that is a Mach4 issue. Go ask on the Mach4 Support forums about that. You are the 2nd person on these forums in the past couple weeks to have that error.
The message about bumping the RPM, it looks like you did an "S250" command, and the PMDX plug-in has its spindle settings for 10% minimum spindle PWM. And since it bumped to 360, I presume your max spindle RPM is 3600. The 1.4V on the AVI is high for 10% duty cycle (should be 1.0V), but the PMDX-407 is non-linear at low speeds, so that my be OK. If you set the RPM for 1800 (50% of the presumed 3600 max) you should see around 5.0V, and at 3600 RPM you should see very close to 10.0V.
Now the voltage readings on the MI1 and MI2 are not right. Both being at 0V does look like the VFD is being commanded both FED and REV at the same time. I couldn't make out the indicators in the pictures as they were pretty low resolution pictures. So... can you post a drawing of all of the connections from the PMDX boards to the VFD. Or a detailed text description? Also, the manual I found mentioned a "SW1" switch to select NPN or PNP connections to MI1 and MI2, though I'm not sure that manual covers your drive and the pictures in the manual show a different control panel than you have. If you *DO* have a "SW1" switch, how do you have the VFD's SW1 set - to "NPN" or "PNP"? And finally, how do you have the Mach4 spindle output signals configured ("Spindle On", "Spindle Fwd" and "Spindle Rev" - hint, you only need either the Fwd or Rev configured).
If SW1 is set to "NPN" and you are using the PMDX-416's relay to control the FWD/REV signals, you should have the relay COM tied to the VFD's "DCM" terminal. Then the relay's "N/O" (normally open) terminal to (usually) the REV and the "N/C" (normally closed" terminal to the VFD "FWD". That presumes you have the Mach4 "Spindle Fwd" signal configured to control the relay and have the polarity set to "positive" (i.e. red "X" in the active low column). If your VFD is looking for PNP-style conntections (i.e. switches between MI1 and 24V) then you need to tie the 24V VFD terminal to the PMX-216's relay "COM".