When trying to Schedule an article for publication: An unexpected error has occurred. Please reload the page and try again

Describe the issue or problem
I have an article at production stage which as also been assigned to an issue. When I click on on Save it returns: An unexpected error has occurred. Please reload the page and try again.

It also returns the same error when I try to schedule it for publication by clicking the “schedule for publication” button. However, despite the error I notice it actually actually effected the command and the button changes to “Unschedule”.

What application are you using?
For example, OJS 3.4.0-9

Additional information
I removed the trace line to reduce the length of the error.

[07-Jun-2025 13:10:00 UTC] PHP Warning: foreach() argument must be of type array|object, null given in /home/slidenaf/public_html/journals.slidenafrica.com/lib/pkp/classes/submission/SubmissionKeywordDAO.php on line 72
[07-Jun-2025 13:10:00 UTC] Slim Application Error:
Type: Illuminate\Database\QueryException
Code: HY000
Message: SQLSTATE[HY000]: General error: 1615 Prepared statement needs to be re-prepared (SQL: DELETE FROM controlled_vocab_entries WHERE controlled_vocab_entry_id = 1)
File: /home/slidenaf/public_html/journals.slidenafrica.com/lib/pkp/lib/vendor/laravel/framework/src/Illuminate/Database/Connection.php
Line: 760
Previous error:
Type: PDOException
Code: HY000
Message: SQLSTATE[HY000]: General error: 1615 Prepared statement needs to be re-prepared
File: /home/slidenaf/public_html/journals.slidenafrica.com/lib/pkp/lib/vendor/laravel/framework/src/Illuminate/Database/Connection.php
Line: 570
View in rendered output by enabling the “displayErrorDetails” setting.

Hi @TSoretire ,It seems to be a problem with the MySQL configuration parameters.
The value of Opened_tables is extremely high, indicating that the cache is too small, leading to frequent table openings. You can check the current table_open_cache setting:

show global status like 'open%tables%';
show variables like '%table_open_cache%';

Hello @deanting. Thanks for the reply. My delay in responding is due to differences in time zone. Below is the the current table_open_cache setting:.

Variable_name Value
Open_tables 8000
Opened_tables 76575589
table_open_cache 8000
table_open_cache_instances 16

Hi @TSoretire , if you are using shared hosting, please disable the ModSec on your hosting server.