follow instructions for manual update deleting everything but the folders in the instructions. This made my site visible again, then incompatible extensions should be disabled by default, do not force enable them or you will have to redo the whole procedure. This worked for me, twice :)

I'm missing some plugins due to lack of upgrades and while trying to enable some of them the gallery went down, had to do the whole manual install but it worked every time, that's why I'm confident its not an install issue but something that is not compatible in your actual setup

Hey Brian --

Just to say I have encountered the identical problem and I have posted my experience in this thread. 

So far no solution.

Russ

BrianO10 wrote:

Hi Folks,
I just upgraded to 12.1.0 from 11.5 (I believe) and the Admin interface (all parts of it) results in the error shown below.  My website was working well before the upgrade.  The normal user interface (seeing the albums and photos) still works, but always throws this error when I try to access the Admin functions.  Any suggestions on how to recover?  I have a backup but would like to understand/fix this.
Thanks for any help you can provide,
Brian


Warning: Use of undefined constant LOUNGE_TABLE - assumed 'LOUNGE_TABLE' (this will throw an Error in a future version of PHP) in *****.com/Piwigo/admin/include/functions.php on line 3271



Warning:  [mysql error 1146] Table '******_db.LOUNGE_TABLE' doesn't exist

SELECT
    image_id
  FROM LOUNGE_TABLE
; in *******.com/Piwigo/include/dblayer/functions_mysqli.inc.php on line 864


Fatal error: Uncaught Error: Call to a member function fetch_assoc() on bool in *****.com/Piwigo/include/dblayer/functions_mysqli.inc.php:925 Stack trace: #0 *******.com/Piwigo/admin/include/functions.php(3273): query2array('\nSELECT\n ima...', NULL, 'image_id') #1 *****.com/Piwigo/admin.php(254): get_orphans() #2 {main} thrown in *****.com/Piwigo/include/dblayer/functions_mysqli.inc.php on line 925

PEU wrote:

You need to upgrade PHP to 7.4 methinks

According to the documentation:

Minimum Requirements

a webserver like Nginx or Apache
MySQL 5 (or the equivalent with MariaDB)
PHP 5.3 (recommended 7.0 or 7.1)

paulleslie wrote:

I have the same problem I think!

That's not the same. One is the LOUNGE_TABLE constant being undefined, your's is the (already resolved constant) piwigo_lounge table not existing.

Try if [Forum, post 182050 by erAck in topic 31634] Admin-interface doesnt work after upgrade to 12.1 helps.

The error 1146 is the same because the table name passed in the SQL command does not exist.
The names passed and causes are different (though might be related).

Hi, this is my first time working with Piwigo. In reading the threads I think I have the same problem with the Admin interface and maybe more. After the upgrade I got 2 set of messages, the first is similar to what other people have and I contacted my host provider to ensure I was moved up to PHP 7.4. After that was done, I went back to see if I could get into Admin and was not able to, but was able to browse and view the gallery and did see warning messages for the plugin Meta. Problem is I'm still not able to get pass the Admin error messages.

Warning:  [mysql error 1146] Table 'toro1893_piwi343.piwiin_lounge' doesn't exist

SELECT
    image_id
  FROM piwiin_lounge
; in /home/toro1893/public_html/dir/include/dblayer/functions_mysqli.inc.php on line 847


Fatal error: Uncaught Error: Call to a member function fetch_assoc() on bool in /home/toro1893/public_html/dir/include/dblayer/functions_mysqli.inc.php:908 Stack trace: #0 /home/toro1893/public_html/dir/admin/include/functions.php(3273): query2array('\nSELECT\n ima...', NULL, 'image_id') #1 /home/toro1893/public_html/dir/admin.php(263): get_orphans() #2 {main} thrown in /home/toro1893/public_html/dir/include/dblayer/functions_mysqli.inc.php on line 908

The 2nd set of messages I'm not sure if it related: here's part of it as it is very long:

Warning:  [mysql error 1146] Table 'toro1893_piwi343.piwiin_lounge' doesn't exist

SELECT
    image_id
  FROM piwiin_lounge
; in /home/toro1893/public_html/dir/include/dblayer/functions_mysqli.inc.php on line 847


Fatal error: Uncaught Error: Call to a member function fetch_assoc() on bool in /home/toro1893/public_html/dir/include/dblayer/functions_mysqli.inc.php:908 Stack trace: #0 /home/toro1893/public_html/dir/admin/include/functions.php(3273): query2array('\nSELECT\n ima...', NULL, 'image_id') #1 /home/toro1893/public_html/dir/admin.php(263): get_orphans() #2 {main} thrown in /home/toro1893/public_html/dir/include/dblayer/functions_mysqli.inc.php on line 908

Please let me know what I need to do to make it working again. Appreciate your help...LouiseC