In short: the software is blind. It cannot find or interpret its roadmap.
Did this happen after a or a new installation ? tecdoc loading data failed check the configuration file
If the basic steps fail, it is time to get your hands dirty. The exact location and name of the configuration file vary depending on your TecDoc product (TecDoc One, TecDoc WebService, TecDoc Offline Client). Below are the most common scenarios. In short: the software is blind