I have tested ShinyFMBN nor DairyFMBN with R.4.0.0 and with Bioconductor 3.11, and, as far as I can see, they both work. My advice is to check that if you have R 4.0 you should upgrade Bioconductor (the installation script does not check if the Bioconductor version installed in the system is the latest). Older version of R (3.6.3) Bioconductor (3.10) are still available for download. I will do any patching needed for compatibility as soon as I have time.