Project Build Error PRJ0009
Build log could not be opened for writing.
Make sure that the file is not open by another process and is not write-protected.
After setting the Build Logging property to Yes and performing a build or rebuild, Visual C++ was unable to open the build log in exclusive mode.
Inspect the Build Logging setting by opening the Options dialog box (on the Tools menu, click Options command) and then selecting VC++ Build in the Projects folder. The build file is called BuildLog.htm and is written to the intermediate directory $(IntDir).
Possible reasons for this error:
You are running two processes of Visual C++ and trying to build the same configuration of the same project in both simultaneously.
The build log file is opened in a process that locks the file.
The user does not have permission to create a file.
The current user does not have write access to the file BuildLog.htm.