From the first thread, there's a stack trace of the error:

Caught exception DBQueryError: A database error has occurred. Did you forget to run maintenance/update.php after upgrading? See: https://www.mediawiki.org/wiki/Manual:Upgrading#Run_the_update_script
Query: INSERT INTO /*Q*/L10N_CACHE (lc_lang,lc_key,lc_value) VALUES (:lc_lang, :lc_key, )
Function: DatabaseOracle::insertOneRow
Error: 936 ORA-00936: missing expression

#0 /var/www/html/devinsample/mediawiki-1.23.1/includes/db/DatabaseOracle.php(709): DatabaseOracle->reportQueryError('ORA-00936: miss...', 936, 'INSERT INTO /*Q...', 'DatabaseOracle:...')
#1 /var/www/html/devinsample/mediawiki-1.23.1/includes/db/DatabaseOracle.php(576): DatabaseOracle->insertOneRow('l10n_cache', Array, 'LCStoreDB::set')
#2 /var/www/html/devinsample/mediawiki-1.23.1/includes/cache/LocalisationCache.php(1229): DatabaseOracle->insert('l10n_cache', Array, 'LCStoreDB::set')
#3 /var/www/html/devinsample/mediawiki-1.23.1/includes/cache/LocalisationCache.php(963): LCStoreDB->set('messages:nov', 'nov')
#4 /var/www/html/devinsample/mediawiki-1.23.1/includes/cache/LocalisationCache.php(452): LocalisationCache->recache('da')
#5 /var/www/html/devinsample/mediawiki-1.23.1/includes/cache/LocalisationCache.php(326): LocalisationCache->initLanguage('da')
#6 /var/www/html/devinsample/mediawiki-1.23.1/includes/cache/LocalisationCache.php(260): LocalisationCache->loadItem('da', 'fallback')
#7 /var/www/html/devinsample/mediawiki-1.23.1/languages/Language.php(4146): LocalisationCache->getItem('da', 'fallback')
#8 /var/www/html/devinsample/mediawiki-1.23.1/languages/Language.php(237): Language::getFallbacksFor('da')
#9 /var/www/html/devinsample/mediawiki-1.23.1/languages/Language.php(196): Language::newFromCode('da')
#10 /var/www/html/devinsample/mediawiki-1.23.1/maintenance/eval.php(81) : eval()'d code(1): Language::factory('da')
#11 /var/www/html/devinsample/mediawiki-1.23.1/maintenance/eval.php(81): eval()
#12 {main}

In LocalisationCache.php it does:

$this->batch[] = array(
'lc_lang' => $this->currentLang,
'lc_key' => $key,
'lc_value' => $this->dbw->encodeBlob( serialize( $value ) ) );

if ( count( $this->batch ) >= 100 ) {
$this->dbw->insert( 'l10n_cache', $this->batch, METHOD );
$this->batch = array();
}

DatabaseOracle.php has:

function encodeBlob( $b ) {
return new Blob( $b );
}

So it returns an object (Database.php returns just the same $b untouched)

insertOneRow has the call to $this->isQuotedIdentifier( $val ), which has the call to strpos() of that value, which is a Blob() object

• This bug has been marked as a duplicate of bug 64970 ***

Seems that the patch from the other bug doesn't address comment 1 and so does not fix this bug.

Reopening

• Bug 68877 has been marked as a duplicate of this bug. ***

• Bug 71251 has been marked as a duplicate of this bug. ***

Heads-up: As per RFC discussion in August 2019, the previously experimental support for using Oracle or MSSQL as database backends in MediaWiki core has been removed in MediaWiki 1.34, so this task might end up as declined in the future.