After Host upgraded the DNS server, OJS start giving me the error

My web host changed the DNS server yesterday. Since them, I am facing problem on my OJS site.
At the front end of the website, I don’t see any issue. I can see all the submissions in the dashboard but when I click on any of the submission or menu items in the dashboard it gives me HTTP 500 error message.
I tried to trace in PHP error log but nothing convincing only warnings…

I turned on the following in config.inc.php based on the hint from another post on the forum
show_stacktrace = On
display_errors = On
Then only I saw the following error message

Deprecated : Methods with the same name as their class will not be constructors in a future version of PHP; ADODB_Cache_File has a deprecated constructor in /home/seisense/journal.seisense.com/lib/pkp/lib/adodb/adodb.inc.php on line 263

Deprecated : Methods with the same name as their class will not be constructors in a future version of PHP; ADOConnection has a deprecated constructor in /home/seisense/journal.seisense.com/lib/pkp/lib/adodb/adodb.inc.php on line 359

Deprecated : Methods with the same name as their class will not be constructors in a future version of PHP; ADORecordSet has a deprecated constructor in /home/seisense/journal.seisense.com/lib/pkp/lib/adodb/adodb.inc.php on line 2921

Deprecated : Methods with the same name as their class will not be constructors in a future version of PHP; ADORecordSet_array has a deprecated constructor in /home/seisense/journal.seisense.com/lib/pkp/lib/adodb/adodb.inc.php on line 3939

Deprecated : The each() function is deprecated. This message will be suppressed on further calls in /home/seisense/journal.seisense.com/lib/pkp/lib/adodb/adodb.inc.php on line 1003

Warning : Declaration of JatsTemplatePlugin::register($category, $path) should be compatible with LazyLoadPlugin::register($category, $path, $mainContextId = NULL) in /home/seisense/journal.seisense.com/plugins/generic/jatsTemplate/JatsTemplatePlugin.inc.php on line 0

Warning : file_put_contents(/home/seisense/journal.seisense.com/cache/fc-pluginSettings-1-defaultthemeplugin.php): failed to open stream: Permission denied in /home/seisense/journal.seisense.com/lib/pkp/classes/cache/FileCache.inc.php on line 90

Warning : file_put_contents(/home/seisense/journal.seisense.com/cache/fc-pluginSettings-1-defaultmanuscriptchildthemeplugin.php): failed to open stream: Permission denied in /home/seisense/journal.seisense.com/lib/pkp/classes/cache/FileCache.inc.php on line 90

Warning : Declaration of CustomBlockPlugin::getBlockContext() should be compatible with BlockPlugin::getBlockContext($contextId = NULL) in /home/seisense/journal.seisense.com/plugins/generic/customBlockManager/CustomBlockPlugin.inc.php on line 0

Warning : Declaration of DRIVERDAO::setOAI(&$oai) should be compatible with PKPOAIDAO::setOAI($oai) in /home/seisense/journal.seisense.com/plugins/generic/driver/DRIVERDAO.inc.php on line 19

Warning : file_put_contents(/home/seisense/journal.seisense.com/cache/fc-pluginSettings-1-lensgalleyplugin.php): failed to open stream: Permission denied in /home/seisense/journal.seisense.com/lib/pkp/classes/cache/FileCache.inc.php on line 90

Fatal error : Uncaught → Smarty: unable to write file /home/seisense/journal.seisense.com/cache/t_compile/wrt5e2ee92ebc46a6_38073437 ← thrown in /home/seisense/journal.seisense.com/lib/pkp/lib/vendor/smarty/smarty/libs/sysplugins/smarty_internal_runtime_writefile.php on line 60

I amusing
OJS 3.1.2.1
PHP 7.2

Please guide me on how to fix this issue.
Thanks

Hi @seisense

The only error in that list that matters is the last one, the Fatal Error. It looks like the permissions on your /cache directory are no longer correct. They (and the subdirectories inside of them) should be writable by the user your journal runs as.

Cheers,
Jason

@jnugent thanks for throwing the hint. I just changed the permission of journal root folder from 744 to 750 and everything is back to normal.
Can anyone suggest if permission level is ok or any security risk?
Thanks