Error in rep(" ", len) : invalid 'times' argument - r

Question

library(OneR)
library(RWeka)
loan_train <- read.csv("loan_train.csv")
loan_test <- read.csv("loan_test.csv")
loan_train <- optbin(loan_train, method = "logreg", na.omit = TRUE)
loan_test <- optbin(loan_test, method = "logreg", na.omit = TRUE)
#Task 1
loan_1R <- OneR(bad_loans ~ ., data = loan_train)
loan_1R
loan_JRip <- JRip(bad_loans ~ ., data = loan_train)
loan_JRip
Need some help with my code. I am able to run everything but for some reason, every time I print loan_1R, it gives me an error. Tried using traceback() but have no idea what it means. My csv file can be in the link below.
https://drive.google.com/file/d/1139FUSXUc_fdzgtKAleo5bGAtjcVGoRC/view?usp=sharing
Error in rep(" ", len) : invalid 'times' argument
In addition: Warning message:
In max(nchar(names(model$rules))) :
no non-missing arguments to max; returning -Inf
> traceback()
3: cat("If ", model$feature, " = ", names(model$rules[iter]), rep(" ",
len), " then ", model$target, " = ", model$rules[[iter]],
"\n", sep = "")
2: print.OneR(x)
1: function (x, ...)
UseMethod("print")(x)
> sessionInfo()
R version 3.4.1 (2017-06-30)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows >= 8 x64 (build 9200)
Matrix products: default
locale:
[1] LC_COLLATE=English_Singapore.1252 LC_CTYPE=English_Singapore.1252
[3] LC_MONETARY=English_Singapore.1252 LC_NUMERIC=C
[5] LC_TIME=English_Singapore.1252
attached base packages:
[1] stats graphics grDevices utils datasets methods base
other attached packages:
[1] RWeka_0.4-37 OneR_2.2
loaded via a namespace (and not attached):
[1] compiler_3.4.1 tools_3.4.1 grid_3.4.1 rJava_0.9-9 RWekajars_3.9.2-1

Answer 1

After hours of testing i found out the problem but I have no idea why it is so. Think that it has something to do with the library(RWeka) package.... Placing library(RWeka) after the OneR code seemed to make it run. But this means i encounter the error only once i run the library(RWeka). Any workaround this?
library(OneR)
loan_train <- read.csv("loan_train.csv")
loan_test <- read.csv("loan_test.csv")
loan_train <- optbin(loan_train, method = "logreg", na.omit = TRUE)
loan_test <- optbin(loan_test, method = "logreg", na.omit = TRUE)
#Task 1
loan_1R <- OneR(bad_loans ~ ., data = loan_train)
loan_1R
library(RWeka)
loan_JRip <- JRip(bad_loans ~ ., data = loan_train)
loan_JRip