Plotting stops after 10 hours of measurement, measurement continues

[MerlinSmiles]

Steps to reproduce

1. Create a measurement of multiple parameters and dimensions
2. Run the measurement for a long time i.e. 10 hours
3. Plot the data in ´Qc.QtPlot´ (I only plotted the z-values, no x,y)

Expected behaviour

The Data should be plotted while it is beeing measured

Actual behaviour

The plotting stops after 10h, while the measurement continues.
The notebook is unresponsive.

System

operating system
Windows 7

qcodes branch
Merge of Master, Merlins instruments, array id names, file location formatter

@alexcjohnson @giulioungaretti