I'm trying to find out if it is possible to use a project that was developed in ASPNetMaker2020 in ASPNetmaker2024. Has anybody any experience with this step? Or should I do it stepwise, migrate step by step to 2021, 2022, 2023?
Just open by v2024 directly. Also read Migrating to v2024.
Actually I did, but I get a lot of errors like ': Cannot convert null literal to non-nullable reference type', nio clue how to solve this.
Since v2022, nullable reference types is used, you may need to update your server events to resolve warnings, see Learn techniques to resolve nullable warnings.
If you have server event codes, comment them first and then uncomment them one by one.