XLL+ Class Library (7.0)

Compiler Error C1083

When building a project, the compiler fails with error C1083

Symptoms

When compiling an XLL+ project, the following error occurs:

fatal error C1083: Cannot open include file: 'xllplus.h': No such file or directory

Summary

  1. When the project is generated by the XLL+ AppWizard, the path to the directory containing the XLL+ header files is added to the project's INCLUDE path.
  2. If this path is incorrect, or if the header files or the project are later moved, then the header files will not be found.
  3. Use the project Settings dialog to fix the problem in an existing project.
  4. If necessary, you should also correct the XLL+ include path the next time you use the XLL+ AppWizard.

Procedure for fixing the problem

In the Project Settings dialog, select the C/C++ / General category, and correct the field Additional Include Directories, as shown below. Note that you will need to do this for both configurations, Debug and Release.

Next, still in the Project Settings dialog, select the Resources / General category, and correct the field Additional Include Directories, as shown below. Note that you will need to do this for both configurations, Debug and Release.

To prevent the problem recurring, you should also correct the setting in the XLL+ / General options dialog. (You can open this by using the Tools/Options menu and selecting the XLL+ / General node, or by using the XLL+ Options command). The property "IncludePath" is in the "Project" category, as shown below.

You should also ensure at this time that the path to the directory containing the XLL+ run-time libraries, such as xlllibr.lib, is correct.