In cases where Git LFS requests lead to an error, the message contains "\n" characters, which are invalid in the json response (and can cause the client not to show the message)
For an authentication error, as an example, the server returns the following json response:
Note that after "Not authenticated" the message contains two "\n" characters.
The git lfs command-line client is unable to parse the message, and instead shows the following:
A workaround, to see the actual error message, is to enable git debug logging (eg GIT_TRACE=1)