Assuming you have a clean environment, here is the exact workflow for "DevExpress VCL 19.1.2 Full Source with DxAutoInstaller 2.2.2."
You might wonder: Why use a 6-year-old library? DevExpress VCL 19.1.2 Full Source with DxAutoInstaller 2.2.2
Released in mid-2019, version 19.1.2 arrived with key enhancements: Assuming you have a clean environment, here is
This version supports RAD Studio 10.3 Rio (and earlier back to XE2). It remains popular because it predates radical licensing changes and the removal of certain legacy controls. This version supports RAD Studio 10
Cause: Leftover DCUs from previous DevExpress installations.
Solution: Delete all *.dcu, *.dcp, *.bpl from your DevExpress source folder. Use the "Clean" button in DxAutoInstaller.
Launch Delphi/C++Builder. Look for "DevExpress" tabs in the Tool Palette. Compile a minimal test project (e.g., drop TdxComponentPrinter and a TcxGrid onto a form). Build and run.
Troubleshooting tip: If you see "Unit not found: cxClasses", manually add %DevExpressSource%\ExpressLibrary\Sources to the IDE’s Library Path.