Filter conflicts with filter in slot `x`

Encountered an odd error when using the fCPUs in-game, attempting to mov a value from a register into one of the out registers and receive the following error:

Line 27: Filter conflicts with filter in slot 7

Program in question

# prefiltered to green rarity as input, since we can't
# operate on quality markers?
# We've got what, 4 filter slots?
# so we just need to grab the top 4
clr mem1
clr mem2
clr mem3
clr r3
mov r10 2
xmov mem1 green
xclt mem2 mem1 5000
# need to select 4 signals from filtered set in mem2
# want it to be random which are picked
:loopouter
clr out
clr r1 
clr r2
:startloop
inc r1
rnd r2 0 cnm2
floor r2
add r3 r1 3
mov r@3 mem2@2
add r@3 2
tlt r1 4
jmp :startloop
mov out1 r4
mov out2 r5
mov out3 r6
mov out4 r7

slp 50
jmp :loopouter

I think this is related to/duplicate of this report on the Factorio modpage, but figured I'd report it here as well just in case.

Modlist

base 2.0.23
bobinserters 1.3.2
Bottleneck 0.12.1
elevated-rails 2.0.23
flib 0.15.0
informatron 0.4.0
quality 2.0.23
Robot256Lib 2.0.6
SpidertronEnhancements 1.10.5
vehicle-wagon-graphics 1.0.0
fcpu 0.4.33
space-age 2.0.23
VehicleWagon2 4.1.5
aai-signal-transmission 0.5.0
EditorExtensions 2.4.0
SpidertronPatrols 2.5.3
visible-planets 1.2.4

I can upload my savefile if that would be helpful, or probably recreate it in a blank/testing world to make debug easier