After I upgraded to Magento 2.3, running the command setup:di:compile, I get this error:
Area configuration aggregation... 5/7 [====================>-------] 71% 58
secs 276.0 MiB
In ClassReader.php line 35:
Class Magento\Email\Model\Source\Variables does not exist
In ClassReader.php line 29:
Class Magento\Email\Model\Source\Variables does not exist
setup:di:compile
I've checked the database setup_module to ensure no mismatch or missing scheme/data versions but all are ok.