entity fishing service not starting on Pop-Os

[albamath]

I am running Pop-Os which is a Linux distro, based on Ubuntu 20.04.
I followed the instructions to install and run entity-fishing from the doc:
https://nerd.readthedocs.io/en/latest/build.html
In particular, I did install grobid and grobid-ner, and I copied all the compiled indexed data to the directory defined in data/config/**.conf.
I checked that those files were non-empty.

But still, when I run ./gradlew appRun from the entity fishing directory, the service does not start. In the logs, I can see:

07 juil. 2020 09:01.30 [INFO ] KBEnvironment             - /mnt/data/wikipedia/latest/wikidata/wikidataIds.csv is not readable

even though I have the indexed databases downloaded and extracted.