I did migration Magento 1 to Magento 2.3.0 all is good but when I create customer form both of side (front and admin) I got the error related to decrypt even I can not edit the customer when I click on save same error has occurred.
Below error is :
Fatal error: Uncaught TypeError: Return value of Magento\Framework\Encryption\Adapter\SodiumChachaIetf::decrypt() must be of the type string, boolean returned in public_html/vendor/magento/framework/Encryption/Adapter/SodiumChachaIetf.php:68 Stack trace: #0 public_html/vendor/magento/framework/Encryption/Encryptor.php(358): Magento\Framework\Encryption\Adapter\SodiumChachaIetf->decrypt('"\x10\x88\x8E\xB5\x851;H\xB1\x12\xE1aaP...')
#1 /public_html/vendor/dotmailer/dotmailer-magento2-extension/Helper/Data.php(744): Magento\Framework\Encryption\Encryptor->decrypt('IhCIjrWFMTtIsRL...')
#2 /public_html/vendor/dotmailer/dotmailer-magento2-extension/Helper/Data.php(203): Dotdigitalgroup\Email\Helper\Data->getApiPassword(Object(Magento\Store\Model\Website\Interceptor))
#3 public_html/vendor/dotmailer/dotmailer-magento2-extens in /public_html/vendor/magento/framework/Encryption/Adapter/SodiumChachaIetf.php on line 68