Suddenly, when I try to run the "External Merge Tool" from Sourcetree, the tool does not appear. I speak suddenly because it worked the last time I tried. The dialogue remains forever:

In the end, I found that this process is related to visual merging (dunno, how to copy the command line from the Windows task manager):

This process, by the way, does not disappear when I press the interrupt, so someone probably did not do their homework. In fact, I would not notice this if there were six processes on this command line.
These are my settings:

How to fix it? I need to combine the project, and I do not know what to do ...