In certain circumstances, the ActiveReports designer that integrates with the Visual Studio IDE does not display. Here are the possible causes, and how to fix the issue.
To check: Create a new ActiveReports project. Does the designer display? If not, the designer integration may not have occurred during installation or may have become corrupted. To fix: Close Visual Studio, uninstall ActiveReports, and reinstall it.
To check: Create a new ActiveReports project. Does the designer display? If so, the project may have invalid or missing assembly references, or the code-based Section report may have invalid code in the designer-generated code. To fix assembly references: If you upgraded ActiveReports since the project was created, check the project References. If the references have the Specific Version property set to true, the specified Version might not exist on your machine. Here are some things you can do. For each ActiveReports assembly reference:
Compare your project with a new ActiveReports project:
To fix invalid code: In Section Reports (code-based), the designer won't display if the designer-generated code (see below) doesn't reconcile with the report controls added using the designer. This can occur if you manually modify designer-generated code in the .Designer.vb or .Designer.cs file associated with the report. We highly recommend that you never modify designer-generated code in ActiveReports. If you only made small changes, you may be able to fix the report by manually restoring the code to its exact original state, but this is not always possible. To identify designer-generated code: We try to make it easy to spot the "untouchable" code by providing comments like the following.
ActiveReports 10 requires Microsoft® .NET Framework Version 3.5 or higher. The designer won't perform properly if a lower version is targeted. To check: In the Solution Explorer, right-click the project and select Properties. On the Application tab of the properties that appear in the Visual Studio workspace, look at the Target framework property. To fix:Change the target framework of the project to version 3.5 or higher. Here is a Microsoft page with more information. MSDN How to: Target a Version of the .NET Framework