"Visible section not found" at admin login

[josiah_carberry]

I am trying to set up a new installation of CE 2 (whatever the latest version is as of 4 July 2018). Things have been going well until now. When I try to log in to the admin backend, it fails with the message "Visible section not found". Login was working fine all day yesterday.

Since I am completely new to Magento, I have no idea how to go about debugging this.

I see no errors or warnings in the system.log. There are no errors in the Apache error log. Clearing client and server caches seems to have no effect.

It would be nice if a useful error message were displayed, instead of the completely obscure "Visible section not found", but that is another issue. Anyway, what could this be???

[Sunil Patel]

Hello @josiah_carberry

Error msg coming from module-config/Model/Config/Structure.php

line no 215, maybe you don't have permission for tab?

hope it will help you.

[josiah_carberry]

Since the account being use is the admin account with which I
successfully logged in and logged out many times yesterday, I don't see
how this can be a permissions issue. So what changed between last night
and this morning? Only the various cron jobs were run. There were no
errors indicated in the cron log. Does this have anything to do with
misconfigured cookies that might have expired overnight??? Or are we
looking at corrupted data in the database???

[Sunil Patel]

Hello @josiah_carberry

throw new LocalizedException(__('Visible section not found.')); 

comment this thing from Magento\Config\Model\Config\Structure and check it

[josiah_carberry]

If you are suggesting that I comment /out/ that line and then try
logging in again, well, all that does is to stop displaying the error
message. The login still fails. I don't see the point.

[ChrisB1983]

This is also happening to me with Magento 2.2.5, I get randomly logged out and occasionally show the error message "Visible section not found".

Did you ever find a solution?

[josiah_carberry]

No, I never found a solution. I ended up doing a complete reinstall from
scratch - very unsatisfactory.
My intuition tells me that the problem has something to do with
incorrectly defined cookie parameters. I also find it very strange that
this message sometimes flashes on the screen in the context of a login
or logout.