Hi @kamedin, did you get to the bottom of it?
I am facing the same issue, and even the most simple example with a single float parameter does trigger the error.
At first I thought it was related to this thread here, but it does happen with floats too.
As you mentioned it only happens when “Randomise tests” is selected.
(using Juce 7.0.9 and pluginval 1.0.3)