This can be used sometimes to create infinite loop... but when - I don't know
Connecting the negative output to the input has more logic. Before those little black things were bigger before, but I decided to make connections with less curviness... and now I see that their wicks are invisible in. Maybe I will try to make those self-connections to appear above the block, not behind it.
Are you trying to install the new build? Because in it, the first thing to do is to backup all the data and then to update some files because of some new rules that I've made. If you have many projects, and they have many small files, this backup process can take some seconds, maybe minute, but if you decide to close the program in the middle of the process it will hang of course.
When is that disk activity starting? Hitting .ex4 or something else?