need help with errors in betareg analysis

Hi

I'm trying to fit a model in betareg and I'm getting errors, but have no
idea what they mean or how to solve them. Does anyone have experience with
this?

model <- betareg(ACT ~ ST*SoilT, data = actDL_F)

Warning messages:
1: In sqrt(W) : NaNs produced
2: In sqrt(W) : NaNs produced
3: In sqrt(1 + phihat) : NaNs produced

data summaries don't give any na's or problems I can see

summary(actDL_F$ACT)

Min.   1st Qu.    Median      Mean   3rd Qu.      Max. 
0.0006227 0.0505600 0.2163000 0.2643000 0.4084000 0.9994000

summary(actDL_F$ST)

Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
  8.085  29.560  34.760  33.870  39.430  49.610

summary(actDL_F$SoilT)

Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
  17.42   20.95   24.18   24.26   27.21   31.19 


Thanks

Ken

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