KDevelop crashes when you try to create file from template via project tree item context menu. So the reason is because check at kdevplatform/language/codegen/templateclassgenerator.cpp:107 fails: Q_ASSERT(baseUrl.path().endsWith('/')); // assume folder baseUrl created via ProjectBaseItem::Path()::toUrl() and does not contain trailing '/' char. Maybe you remove this check or use QFileInfo()::isDir() for such purposes? Reproducible: Always