I installed DESeq2 by

if (!requireNamespace("BiocManager", quietly = TRUE))
    install.packages("BiocManager")

BiocManager::install("DESeq2")

and when I try to call it from the library I get the following error

Error: package or namespace load failed for ‘DESeq2’:
 objects ‘rowSums’, ‘colSums’, ‘rowMeans’, ‘colMeans’ are not exported by 'namespace:S4Vectors'

I tried deleting manually and reinstalling the package ma nothing changed. I also uploaded R from 3.6.2 to 3.6.3 but it didn't change anything.

Plus, I previously worked with DESeq2 with no problems, and didn't change anything in the meantime.

Thank you in advance for your help.

Can you take a look at some recent threads that cover this topic, e.g. looking at recent posts tagged "deseq2"? We worked through these issues with other users last week.