NativeSessionStorage.php: Failed to start the session: already started by PHP

[Nina]

Meine Logfiles werden unter Contao 4.4 mit dieser Meldung zugespammt (bei Mittwald). Hat jemand eine Idee, was ich da machen kann?

[2017-07-25 09:39:49] app.CRITICAL: An exception occurred. {"exception":"[object] (RuntimeException(code: 0): Failed to start the session: already started by PHP. at /html/c4/vendor/symfony/symfony/src/Symfony/Component/HttpFoundation/Session/Storage/NativeSessionStorage.php:136)"} []

[syntaxys]

Ich habe das gleiche Problem bei alfahosting:

[2019-09-12 10:36:55] request.INFO: Matched route "contao_install". {"route":"contao_install","route_parameters":{"_ro ute":"contao_install","_scope":"backend","_token_c heck":true,"_controller":"Contao\\InstallationBund le\\Controller\\InstallationController::installAct ion"},"request_uri":"https://www.domain.tld/contao/install","method":"POST"} []
[2019-09-12 10:36:55] request.CRITICAL: Uncaught PHP Exception RuntimeException: "Failed to start the session: already started by PHP." at /var/www/webXYZ/html/contao-4.8/vendor/symfony/http-foundation/Session/Storage/NativeSessionStorage.php line 145 {"exception":"[object] (RuntimeException(code: 0): Failed to start the session: already started by PHP. at /var/www/webXYZ/html/contao-4.8/vendor/symfony/http-foundation/Session/Storage/NativeSessionStorage.php:145)"} []
[2019-09-12 10:36:55] request.CRITICAL: Uncaught PHP Exception RuntimeException: "Failed to start the session: already started by PHP." at /var/www/webXYZ/html/contao-4.8/vendor/symfony/http-foundation/Session/Storage/NativeSessionStorage.php line 145 {"exception":"[object] (RuntimeException(code: 0): Failed to start the session: already started by PHP. at /var/www/webXYZ/html/contao-4.8/vendor/symfony/http-foundation/Session/Storage/NativeSessionStorage.php:145)"} []

In der lokalen Entwicklungsumgebung läuft die 4.8.2 problemlos. Hat jemand eine Idee?