It installs and activates fine here (Blender 2.81a, W10).
For a test I made a simple plane emitter, cube domain and plane collider. Then simulated.
But when I played back the sim, it got stuck on 2nd frame.
So I did reset and wanted to bake again (with less particles & lesser resolution) but then it gave me an error:
Traceback (most recent call last):
File "C:\Users\X\AppData\Roaming\Blender Foundation\Blender\2.81\scripts\addons\jet_fluids\bake_particles.py", line 358, in invoke
self.execute(context)
File "C:\Users\X\AppData\Roaming\Blender Foundation\Blender\2.81\scripts\addons\jet_fluids\bake_particles.py", line 283, in execute
self.simulate(offset=frame_start, particles_colors=[])
File "C:\Users\X\AppData\Roaming\Blender Foundation\Blender\2.81\scripts\addons\jet_fluids\bake_particles.py", line 66, in simulate
color = emitter.data.vertex_colors[0].data[loop_index].color
IndexError: bpy_prop_collection[index]: index 0 out of range, size 0
location: <unknown location>:-1
PS
Error is caused by JetFluid Color: Use Color enabled.
Would be good, if you had exemplary scene files available…