Error message id: cannot find name for group ID after logging in

What likely happened is that the UID and GID are provided to the server via LDAP. If the /etc/group file doesn't contain the translation for the GID, then the server administrators likely just failed to update the group definitions. What can you do? Not much. The user id is controlled by the administrator. (Now if you happen to have ROOT privileges, you can add the group into /etc/group. You should also check to see if any other user accounts are using the same group, and if they are, name the group appropriately).

This happened when my user "jackson" wasn't assigned a group. I knew the solo group id for my user was 1000 (when a user is created with $ adduser and no parameters are defined, the user is assigned the next ids available beyond 999. The first getting uid 1000 and gid 1000).

This warning means your user does not belong to a group so what you need to do is to add the user to a group. Either have your admin help you like @sparticvs mentioned or if you have root privileges / it's your machine you can do the following:

$ addgroup [your_user_name]
$ usermod -a -G [your_user_name] [your_user_name]

And that should fix it (untested)

What I did was simply (advanced)

• $ sudo vi /etc/group
• modify the line of web:x:1001: to web:x:1000:jackson

Which made my user jackson belong to the web group.

FYI if you're not familiar with vim I do not recommend the "advanced" steps, if you're really really desperate use $ sudo nano /etc/group