This is complicated to fix, but is a limitation of simulation.
In simple terms this basically means that the 'maths' to generate the waveforms requested simply can't be achieved by the SPICE simulation engine. This is normally caused by bad simulation circuit design, e.g. unconnected nodes.
As an example in this case you have lots of capacitors which are effectively floating at one end via the DIL switch (when in the off position). This gives lots of capacitors that are not connected at one end and so difficult to model.
Start with a very simple model and then gradually add components to get an understanding of where the errors are occurring.