I'm trying to run two scripts on a tv show so the intro is fully deinterlaced and the rest is decombed. I'm getting a conditional filter error on the script below but don't quite understand why.

HTML Code:
a = Trim(0, 1805).QTGMC(TR0=2, TR1=2, TR2=1, Rep0=1, Rep1=0, Rep2=4, DCT=5, ThSCD1=300, ThSCD2=110, SourceMatch=3, Lossless=2, Sharpness=0.1, Sbb=0, MatchPreset="slow", NoiseProcess=2, GrainRestore=0.0, NoiseRestore=0.4, NoisePreset="slow", StabilizeNoise=false, NoiseTR=0, NoiseDeint="bob")

b = Trim(1806, 3000).ConditionalFilter(ChangeFPS(50), QTGMC(TR0=2, TR1=2, TR2=1, Rep0=1, Rep1=0, Rep2=4, DCT=5, ThSCD1=300, ThSCD2=110, SourceMatch=3, Lossless=2, Sharpness=0.1, Sbb=0, MatchPreset="slow", NoiseProcess=2, GrainRestore=0.0, NoiseRestore=0.4, NoisePreset="slow", StabilizeNoise=false, NoiseTR=0, NoiseDeint="bob").QTGMC(InputType=1), ChangeFPS(50), "IsCombedTIVTC(cthresh=2)")

a + b