In case OntoWiki isn’t loaded correctly after you followed this tutorial
Go to ...\htdocs\elds\config.ini and set debug = true. After a restart you should now see an error message in your browser which should hopefully point you to the source of the problem (if not, create an issue).
Error on bootstrapping application: Unable to connect to Virtuoso Universal Server via ODBC
Make sure that the Virtuoso service is started. If it does not start, look for files named virtuoso.lck in your Virtuoso folder under database or virtuoso and delete them if existing.