With the help of google, finally, I found the solution. In fact, the same channel (checked with conda info command) that I had set long back to install R3.2. Because here, they have clearly mentioned the R version but when I was trying to install R4.0 it was not going through the conda-forge channel, instead, it was redirected to a different channel. While trying other solutions I realized that it is something to do with conda channels that I am using. Therefore, again, I started communicating with google about updating R and tried the solutions described above. So, you see? it's not only about Seurat, and I can not simply mess up with my R environment, just to update the Seurat version, right? Because I am working on different projects and to deal with them I have already configured other R packages.

But unfortunately, in my case, it was not an optimal choice. But today I started working on another dataset and there I encountered this error [[=4.0) in one environment and R3.2 in another.

I was using Seurat v3.2 and I did most of my single-cell analysis using this version.

Update anaconda