I have tried this that you put up here but I get the following poster:
"Downloading minecraft server failed, invalid e-tag checksum Try again or manually place server jar to skip download"
Copy the libraries to the .minecraft folder, it should be noted that what I want is to update forge because I have an earlier version and that poster is the one that I get and I don't know what it means with place server jar, where is that file that I need to place manually ? Is it possible to update forge offline in these circumstances?