Re-compile in-process adapters, UDFs, and server plugins when you upgrade Sybase CEP versions.
Code that runs inside the server (such as in-process adapters, UDFs and server plugins) is not necessarily binary compatible from version to version. If you have written your own in-process code, then each time you upgrade your Sybase CEP Engine, re-compile that code and copy it to the appropriate location, such as the server bin directory.
For out-of-process code, on the other hand, you must re-compile only if the API has changed in a way that is not backwards compatible. Such changes are listed in the SybaseCEPReleaseNotes.txt file in the Server doc directory. If you skip over intermediate versions, for example, you jump from version 4.4 to version 5.1, then you may need to read the release notes for each of the intermediate versions to learn about changes that are not backwards compatible.
Upgraded versions of Microsoft Visual Studio .NET if appropriate: When Sybase CEP Engine was upgraded from Version 5.0 to Version 5.1, it required users to upgrade from Microsoft Visual Studio .NET 2003 to Microsoft Visual Studio .NET 2005.
Visual Studio .NET 2005 updates project-related files (for example, .vcproj or .sln), and earlier versions of Visual Studio cannot read the updated files. Therefore, upgrading is irreversible. You must re-create the project-related files in order to downgrade.