Hi @rjha2,
Welcome to the RStudio Community Forum.
I downloaded your .RDS file into my current working directory and was able to read it with no problems:
> input.lst <- readRDS(file="factorList.rds")
> str(input.lst)
List of 3
$ state_fact: Factor w/ 36 levels "1201","1202",..: 1 2 3 4 5 6 7 8 9 10 ...
$ dis_fact : Factor w/ 698 levels "12586327","12586328",..: 1 2 3 4 5 6 7 8 9 10 ...
$ year_fact : Factor w/ 50 levels "1969","1970",..: 1 2 3 4 5 6 7 8 9 10 ...
>
The contents are not a data.frame but a list of three variables as factors each with a different length.
Hope this helps.