when using PlotLine with line coordinates from -DBL_MAX to DBL_MAX the graph disappears, only a grey area is shown, but no error is generated.
To reproduce this issue, use, e.g., the sample graphlegend and replace the coordinates as shown in the screenshot below (it is taken from the modified sample graphlegend).
The result is the same if these coordinates are used for the X axis instead.
Everything is fine as long only one of these extreme values is used, but both at the same time result in the reported misbehaviour. The same problem is observed for other plotting functions such as PlotRectangle ...