Magento 2.3.1 - Payment methods api

[raul_baricevic]

I have a payment module for Magento 2.2 for one Croatian online payment provider, i tried it to install on Magento 2.3.1 and everything is fine but when i want to go on Checkout it says https://www.example.com/rest/default/V1/guest-carts/auIzs7o1NSN0KyEoq6jHv5MJkbcnUbC7/estimate-shippi... - Failed to load resource: the server responded with a status of 500 () and i have no shipping methods?

reports:

This is list of errorst from my log

debug.log

[2019-06-06 11:57:30] main.CRITICAL: Type Error occurred when creating object: Magento\Framework\Communication\Config\Data, Argument 2 passed to Magento\Framework\Reflection\TypeProcessor::resolveFullyQualifiedClassName() must be of the type string, null given, called in /home/nulledzo/capriolo.hr/vendor/magento/framework/Reflection/TypeProcessor.php on line 535 [] [] [2019-06-06 11:57:30] main.ERROR: Type Error occurred when creating object: Magento\Framework\Communication\Config\Data [] []

system.log

[2019-06-06 11:57:30] main.CRITICAL: Type Error occurred when creating object: Magento\Framework\Communication\Config\Data, Argument 2 passed to Magento\Framework\Reflection\TypeProcessor::resolveFullyQualifiedClassName() must be of the type string, null given, called in /home/nulledzo/capriolo.hr/vendor/magento/framework/Reflection/TypeProcessor.php on line 535 [] [] [2019-06-06 11:57:30] main.ERROR: Type Error occurred when creating object: Magento\Framework\Communication\Config\Data [] []

Report:

{"0":"Type Error occurred when creating object: Magento\Framework\Communication\Config\Data","1":"#1 Magento\Framework\ObjectManager\Factory\Dynamic\Developer->create() called at [vendor/magento/framework/ObjectManager/ObjectManager.php:70]\n#2 Magento\Framework\ObjectManager\ObjectManager->get() called at [vendor/magento/framework/ObjectManager/Factory/AbstractFactory.php:160]\n#3 Magento\Framework\ObjectManager\Factory\AbstractFactory->resolveArgument() called at [vendor/magento/framework/ObjectManager/Factory/AbstractFactory.php:246]\n#4 Magento\Framework\ObjectManager\Factory\AbstractFactory->resolveArgumentsInRuntime() called at [vendor/magento/framework/ObjectManager/Factory/Dynamic/Developer.php:34]\n#5 Magento\Framework\ObjectManager\Factory\Dynamic\Developer->_resolveArguments() called at [vendor/magento/framework/ObjectManager/Factory/Dynamic/Developer.php:59]\n#6 Magento\Framework\ObjectManager\Factory\Dynamic\Developer->create() called at [vendor/magento/framework/ObjectManager/ObjectManager.php:70]\n#7 Magento\Framework\ObjectManager\ObjectManager->get() called at [vendor/magento/framework/ObjectManager/Factory/AbstractFactory.php:160]\n#8 Magento\Framework\ObjectManager\Factory\AbstractFactory->resolveArgument() called at [vendor/magento/framework/ObjectManager/Factory/AbstractFactory.php:246]\n#9 Magento\Framework\ObjectManager\Factory\AbstractFactory->resolveArgumentsInRuntime() called at [vendor/magento/framework/ObjectManager/Factory/Dynamic/Developer.php:34]\n#10 Magento\Framework\ObjectManager\Factory\Dynamic\Developer->_resolveArguments() called at [vendor/magento/framework/ObjectManager/Factory/Dynamic/Developer.php:59]\n#11 Magento\Framework\ObjectManager\Factory\Dynamic\Developer->create() called at [vendor/magento/framework/ObjectManager/ObjectManager.php:70]\n#12 Magento\Framework\ObjectManager\ObjectManager->get() called at [vendor/magento/framework/ObjectManager/Factory/AbstractFactory.php:160]\n#13 Magento\Framework\ObjectManager\Factory\AbstractFactory->resolveArgument() called at [vendor/magento/framework/ObjectManager/Factory/AbstractFactory.php:246]\n#14 Magento\Framework\ObjectManager\Factory\AbstractFactory->resolveArgumentsInRuntime() called at [vendor/magento/framework/ObjectManager/Factory/Dynamic/Developer.php:34]\n#15 Magento\Framework\ObjectManager\Factory\Dynamic\Developer->_resolveArguments() called at [vendor/magento/framework/ObjectManager/Factory/Dynamic/Developer.php:59]\n#16 Magento\Framework\ObjectManager\Factory\Dynamic\Developer->create() called at [vendor/magento/framework/ObjectManager/ObjectManager.php:70]\n#17 Magento\Framework\ObjectManager\ObjectManager->get() called at [vendor/magento/framework/ObjectManager/Factory/AbstractFactory.php:160]\n#18 Magento\Framework\ObjectManager\Factory\AbstractFactory->resolveArgument() called at [vendor/magento/framework/ObjectManager/Factory/AbstractFactory.php:246]\n#19 Magento\Framework\ObjectManager\Factory\AbstractFactory->resolveArgumentsInRuntime() called at [vendor/magento/framework/ObjectManager/Factory/Dynamic/Developer.php:34]\n#20 Magento\Framework\ObjectManager\Factory\Dynamic\Developer->_resolveArguments() called at [vendor/magento/framework/ObjectManager/Factory/Dynamic/Developer.php:59]\n#21 Magento\Framework\ObjectManager\Factory\Dynamic\Developer->create() called at [vendor/magento/framework/ObjectManager/ObjectManager.php:70]\n#22 Magento\Framework\ObjectManager\ObjectManager->get() called at [vendor/magento/framework/ObjectManager/Factory/AbstractFactory.php:160]\n#23 Magento\Framework\ObjectManager\Factory\AbstractFactory->resolveArgument() called at [vendor/magento/framework/ObjectManager/Factory/AbstractFactory.php:246]\n#24 Magento\Framework\ObjectManager\Factory\AbstractFactory->resolveArgumentsInRuntime() called at [vendor/magento/framework/ObjectManager/Factory/Dynamic/Developer.php:34]\n#25 Magento\Framework\ObjectManager\Factory\Dynamic\Developer->_resolveArguments() called at [vendor/magento/framework/ObjectManager/Factory/Dynamic/Developer.php:59]\n#26 Magento\Framework\ObjectManager\Factory\Dynamic\Developer->create() called at [vendor/magento/framework/ObjectManager/ObjectManager.php:70]\n#27 Magento\Framework\ObjectManager\ObjectManager->get() called at [vendor/magento/framework/ObjectManager/Factory/AbstractFactory.php:196]\n#28 Magento\Framework\ObjectManager\Factory\AbstractFactory->parseArray() called at [vendor/magento/framework/ObjectManager/Factory/AbstractFactory.php:172]\n#29 Magento\Framework\ObjectManager\Factory\AbstractFactory->resolveArgument() called at [vendor/magento/framework/ObjectManager/Factory/AbstractFactory.php:246]\n#30 Magento\Framework\ObjectManager\Factory\AbstractFactory->resolveArgumentsInRuntime() called at [vendor/magento/framework/ObjectManager/Factory/Dynamic/Developer.php:34]\n#31 Magento\Framework\ObjectManager\Factory\Dynamic\Developer->_resolveArguments() called at [vendor/magento/framework/ObjectManager/Factory/Dynamic/Developer.php:59]\n#32 Magento\Framework\ObjectManager\Factory\Dynamic\Developer->create() called at [vendor/magento/framework/ObjectManager/ObjectManager.php:70]\n#33 Magento\Framework\ObjectManager\ObjectManager->get() called at [vendor/magento/framework/ObjectManager/Factory/AbstractFactory.php:160]\n#34 Magento\Framework\ObjectManager\Factory\AbstractFactory->resolveArgument() called at [vendor/magento/framework/ObjectManager/Factory/AbstractFactory.php:246]\n#35 Magento\Framework\ObjectManager\Factory\AbstractFactory->resolveArgumentsInRuntime() called at [vendor/magento/framework/ObjectManager/Factory/Dynamic/Developer.php:34]\n#36 Magento\Framework\ObjectManager\Factory\Dynamic\Developer->_resolveArguments() called at [vendor/magento/framework/ObjectManager/Factory/Dynamic/Developer.php:59]\n#37 Magento\Framework\ObjectManager\Factory\Dynamic\Developer->create() called at [vendor/magento/framework/ObjectManager/ObjectManager.php:70]\n#38 Magento\Framework\ObjectManager\ObjectManager->get() called at [vendor/magento/framework/App/Http.php:135]\n#39 Magento\Framework\App\Http->launch() called at [generated/code/Magento/Framework/App/Http/Interceptor.php:24]\n#40 Magento\Framework\App\Http\Interceptor->launch() called at [vendor/magento/framework/App/Bootstrap.php:258]\n#41 Magento\Framework\App\Bootstrap->run() called at [index.php:39]\n</pre>","url":"/rest/default/V1/guest-carts/auIzs7o1NSN0KyEoq6jHv5MJkbcnUbC7/estimate-shipping-methods","script_name":"/index.php"}

[joanmarc]

Same issue after upgrade from 2.1.8, any workaround?