You get this error after you activated to use graphical information in your documentation
This is a known problem but not considered as bug. You are using the Dot tool to generate Graphical information and this returns the "error opening map file". To solve this problem you just have to set the variable "SHORT_NAMES" to yes. You can do this easily in the Expert view of the Doxygen GUI on the Project tab. Here you just have to check the checkbox for SHORT_NAMES. You save your configuration and run doxygen again.
Everything will be fine.
About the Author
Wim Peeters is electronics engineer with an additional master in IT and over 30 years of experience including time spent in support, development, consulting, training and database administration. Wim has worked with SQL Server since version 6.5. He has developed in C/C++, Java and C# on Windows and Linux in different European countries and different European languages. He writes knowledge base articles to solve IT problems and publishes them on the Lubby Knowledge Platform where he is one of the most important contributors and the main developer.