im trying to download that spesific library to make gene annotation but it gives me this warning. can somebody explain why and how can i fix it. Thanks.

if (!require("BiocManager", quietly = TRUE))

• install.packages("BiocManager")

BiocManager::install("illuminaHumanv4.db") Error: Bioconductor version cannot be validated; no internet connection? See #troubleshooting section in vignette

You got an error that said this:

Error: Bioconductor version cannot be validated; no internet connection? See #troubleshooting section in vignette

Which pointed you to the troubleshooting section of the vignette. Have you read that section? Did you try the things it says to try?

I found an answer that worked for me from https://bioinformation.cn/tag/cannot-be-validated/

In brief:

1. Install BiocManager.

install.packages("BiocManager")

1. Download the file from the following link or save the file as a text (.txt) by right-clicking and save as...

https://bioconductor.org/config.yaml

Remove .txt from the name of the file after saving it as a text file. So the file name should be config.yaml

1. Type in R the following code. The path to the saved file should be changed in the following code in R.

options( BIOCONDUCTOR_CONFIG_FILE = "C:/the path to the saved file/config.yaml" )

1. There shouldn't be an error message in the following code.

BiocManager::valid()

1. Now, a package can be installed.

BiocManager::install("fsa")