It's hard to tell exactly what's going on from your description alone.
If you look inside the algstat source code, it seems like that object, markovCode.mat.mar is supposed to be downloaded from a web source, so it's possible that's failing somehow:
However, it does look like that site is up:
https://markov-bases.de/
Could you please turn this into a self-contained reprex (short for reproducible example)? It will help us help you if we can be sure we're all working with/looking at the same stuff.
install.packages("reprex")
If you've never heard of a reprex before, you might want to start by reading the tidyverse.org help page. The reprex dos and don'ts are also useful.
There's also a nice FAQ on how to do a minimal reprex for beginners, below:
What to do if you run into clipboard problems
If you run into problems with access to your clipboard, you can specify an outfile for the reprex, and then copy and paste the contents into the forum.
reprex::reprex(input = "fruits_stringdist.R", outfile = "fruits_stringdist.md")
For pointers specific to the community site, check out the reprex FAQ.