Cannot load mixed objects fitted in older versions

[singmann]

When constructing a model with an old version, e.g.;

require(devtools)
dev_mode()
install_url("https://cran.rstudio.com/src/contrib/Archive/afex/afex_0.13-145.tar.gz")
require(afex)
data(obk.long)
m1 <- mixed(value ~ treatment * phase + (1|id), obk.long)
save(m1, file = "lmm_test.rda")

It cannot be opened in the latest version (after restarting R and loading the latest afex):

require(afex)
load("lmm_test.rda")
m1
## Error in if (attr(object, "method") == "KR") { : 
##  argument is of length zero

(probably a different error if fitted with LRT!!)

[singmann]

Works now (with warning): 746e5ac

##            Effect         F ndf ddf F.scaling      p.value    stat.U ndf.U ddf.U F.scaling.U    p.value.U
## 1       treatment  2.913883   2  13         1 9.004087e-02  2.913883     2    13          NA 9.004087e-02
## 2           phase 36.709113   2 218         1 1.817341e-14 36.709113     2   218          NA 1.817341e-14
## 3 treatment:phase 10.331966   4 218         1 1.112566e-07 10.331966     4   218          NA 1.112566e-07
## Warning message:
## In nice.mixed(x, ...) :
##   mixed object was created with old version of afex, table not nicely formatted.