Backend login fails with no error

Hi,

yes, I have searched the forum and found several reports of the same issue, but none of the proposed fixes worked.

The story: In order to make an update, we copied a site to a subfolder that is accessed via a subdomain. Frontend works fine.
If I enter a wrong username/password in the backend, I get the usual error message. Entering a correct user/password, the page loads again, no error message, and I am immediately locked out. In the database I see three login attempts (but was only one!).

What now?

Thank you!

First of all, the community is not full of "fortune tellers", so more info's about you environment is always necessary.

Second i would guess you have a problem with your /config/pathconfig.php (contao3.0.6 or higher). If you go to the /contao/install.php and type in the install PW your path config will be rewritten. This step is always needed if you move contao on the server around.

If it is not the solution, pls give more details.

Hello ciaobello,

Thanks for your reply. Sorry if I didn't give more information. I just don't know what exactly would be interesting in this case and hoped this would have happened to someone before so he'd have an idea what to check.
This is Contao 2.9.3. I created a copy for an update to 3. I already tried an update to 3 with another copy, but that failed because of non-compatible extensions (event manager and downloadarchive).

Environment is "standard" shared hosting Apache/MySQL. The copy, as I mentioned, is in a subfolder of the same hosting account as the original site, so it's surely not a hosting issue.

Well, well, I had tried the install tool already, because it was mentioned in another thread. It made no difference. But now I tried the same again, and now the login worked! Very strange. But good. Only, I still don't know what went wrong in the first place.
Anyway, thanks a lot ciaobello.

Maybe some kind of cookie issue.