We agree it is not pleasant to have to rewrite portions of long existing projects, but the changes come from the constant work on the reporting engine and the improvements we make to add new features and extend old ones.
To ease the process we aim to provide Upgrade Wizards that handle the upgrade process where possible, and leave minimum manual settings, required by the differences that may exist in different projects and scenarios, which do not allow an automation of the process.
We also started recording in our online help
in details changes and dependencies, which are important on upgrade.
Thus our recommendation is to check the release notes
and the corresponding help article for changes in the reporting engine before proceeding with the upgrade.
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