Running examples in ‘mlmRev-Ex.R’ failed
The error most likely occurred in:

> base::assign(".ptime", proc.time(), pos = "CheckExEnv")
> ### Name: Contraception
> ### Title: Contraceptive use in Bangladesh
> ### Aliases: Contraception
> ### Keywords: datasets
> 
> ### ** Examples
> 
> str(Contraception)
'data.frame':	1934 obs. of  6 variables:
 $ woman   : Factor w/ 1934 levels "1","2","3","4",..: 1 2 3 4 5 6 7 8 9 10 ...
 $ district: Factor w/ 60 levels "1","2","3","4",..: 1 1 1 1 1 1 1 1 1 1 ...
 $ use     : Factor w/ 2 levels "N","Y": 1 1 1 1 1 1 1 1 1 1 ...
 $ livch   : Factor w/ 4 levels "0","1","2","3+": 4 1 3 4 1 1 4 4 2 4 ...
 $ age     : num  18.44 -5.56 1.44 8.44 -13.56 ...
 $ urban   : Factor w/ 2 levels "N","Y": 2 2 2 2 2 2 2 2 2 2 ...
> summary(Contraception)
     woman         district    use      livch         age             urban   
 1      :   1   14     : 118   N:1175   0 :530   Min.   :-13.560000   N:1372  
 2      :   1   1      : 117   Y: 759   1 :356   1st Qu.: -7.559900   Y: 562  
 3      :   1   46     :  86            2 :305   Median : -1.559900           
 4      :   1   25     :  67            3+:743   Mean   :  0.002198           
 5      :   1   6      :  65                     3rd Qu.:  6.440000           
 6      :   1   30     :  61                     Max.   : 19.440000           
 (Other):1928   (Other):1420                                                  
> (fm1 <- glmer(use ~ urban+age+livch+(1|district), Contraception, binomial))
Generalized linear mixed model fit by maximum likelihood (Laplace
  Approximation) [glmerMod]
 Family: binomial  ( logit )
Formula: use ~ urban + age + livch + (1 | district)
   Data: Contraception
      AIC       BIC    logLik -2*log(L)  df.resid 
 2427.616  2466.587 -1206.808  2413.616      1927 
Random effects:
 Groups   Name        Std.Dev.
 district (Intercept) 0.4608  
Number of obs: 1934, groups:  district, 60
Fixed Effects:
(Intercept)       urbanY          age       livch1       livch2      livch3+  
   -1.68965      0.73298     -0.02659      1.10913      1.37634      1.34518  
> (fm2 <- glmer(use ~ urban+age+livch+(urban|district), Contraception, binomial))
Error: Downdated VtV is not positive definite
Execution halted