Mount of device not owned by requested user

Using Ubuntu 18.04. When logging into a tty terminal of a PC, the dmesg lines

[   83.966238] Mount of device (uid: 0) not owned by requested user (uid: 1000)
[   83.966795] Reading sb failed; rc = [-1]

seem to explain this outcome mount: Operation not permitted. Then I am presented with the normal prompt.

The general /home is mounted and I can see /home/user (ls -l home gives drwx------ 4 user user .... user) as well its content.
This error does not occur if I login with another user in the same desktop. This incident is part of a more problematic situation with that user and the loading of the encrypted content. If relevant please see: https://askubuntu.com/q/1372716/446253

I am not familiar with the concept of ownership at mount time. Here, I am trying to isolate the meaning of the dmesg message first.

Which condition can throw that message?
Where should I look at first?

Solution 1:

The following error message is explained as follows:

Mount of device (uid: 0) not owned by requested user (uid: 1000)

• "user (uid: 1000)" is the user that had the problem
• "device (uid: 0)" means that the device was not mounted (has no id).
• "not owned" is the actual error.

The reason for the problem is permissions : The user must be the owner of both home/.ecryptfs/user/.Private and also of home/.ecryptfs/user/.ecryptfs. Owning only one of the two is not enough.