As this - if I understand the message correctly - originates from within the core.
call_user_func#34 //
{closure}# //
TYPO3\CMS\Frontend\Http\Application->run#33 //
TYPO3\CMS\Core\Core\Bootstrap->handleRequest#78 //
TYPO3\CMS\Frontend\Http\RequestHandler->handleRequest#302 //
TYPO3\CMS\Core\Core\Bootstrap->loadExtensionTables#134 //
TYPO3\CMS\Core\Utility\ExtensionManagementUtility::loadExtTables#974 //
TYPO3\CMS\Core\Cache\Frontend\PhpFrontend->requireOnce#1876 //
TYPO3\CMS\Core\Cache\Backend\SimpleFileBackend->requireOnce#77 //
require_once(typo3temp/Cache/Code/cache_core/ext_tables_d9b8e39b9bd0b2cee68920f678d4001ef82f0292.php),typo3_src-7.6.16/typo3/sysext/core/Classes/Cache/Backend/SimpleFileBackend.php#382 //
TYPO3\CMS\Core\Utility\ExtensionManagementUtility::loadNewTcaColumnsConfigFiles#3174 //
TYPO3\CMS\Core\Utility\GeneralUtility::logDeprecatedFunction#1985 (typo3_src-7.6.16/typo3/sysext/core/Classes/Utility/ExtensionManagementUtility.php#1977)
If I check the sysext it is called from
core/Classes/Utility/ExtensionManagementUtility.php:1906: static::loadNewTcaColumnsConfigFiles();
core/Classes/Utility/ExtensionManagementUtility.php:1946: $phpCodeToCache[] = self::class . '::loadNewTcaColumnsConfigFiles();';
core/Classes/Utility/ExtensionManagementUtility.php:1977: public static function loadNewTcaColumnsConfigFiles()
core/Classes/Category/CategoryRegistry.php:105: ExtensionManagementUtility::loadNewTcaColumnsConfigFiles();
core/Tests/Unit/Utility/ExtensionManagementUtilityTest.php:1719: // Tests concerning loadNewTcaColumnsConfigFiles
core/Tests/Unit/Utility/ExtensionManagementUtilityTest.php:1726: public function loadNewTcaColumnsConfigFilesIncludesDefinedDynamicConfigFileIfNoColumnsExist()
core/Tests/Unit/Utility/ExtensionManagementUtilityTest.php:1735: ExtensionManagementUtility::loadNewTcaColumnsConfigFiles();
core/Tests/Unit/Utility/ExtensionManagementUtilityTest.php:1741: public function loadNewTcaColumnsConfigFilesDoesNotIncludeFileIfColumnsExist()
core/Tests/Unit/Utility/ExtensionManagementUtilityTest.php:1753: ExtensionManagementUtility::loadNewTcaColumnsConfigFiles();
install/Classes/Controller/Action/Ajax/ExtensionCompatibilityTester.php:172: ExtensionManagementUtility::loadNewTcaColumnsConfigFiles();
but not from any of the installed extensions in typo3conf.
So the question is why is a function that is depreciated still used in the core.
Appart from possible bad style, it adds additional burden to the execution, as the exception will be thrown and executed each and every time the function is called.
And as it seems that this function is called with each FE-access thru
TYPO3\CMS\Frontend\Http\Application->run#33 //
this is a lot of burden to operational systems I would think.
But I might be misinterpreting something.