Thanks for the tip! I went into the Launcher Properties by right clicking BB as root in the start menu, and changed the command to gksu bleachbit and it works perfectly. Before the edit it was something like su-to-root -X bleachbit (that's probably not exact, I wish I had copied it before I edited it, but I guess it doesn't matter).

What I don't get is that it had worked before today, so what could have possibly changed to make it not work?

So will this rebuilt mate-power-manager find its way into Devuan's repos?

Thanks MiyoLinux. Marking this thread as solved.

Out of curiosity, what does "dpms" stand for?

I did, but when I reinstalled Miyo I kept Slim. So how do I change it with Slim?

Thanks for this bit of knowledge.

Hi MiyoLinux. Thanks for responding. Actually, I did try straight Devuan with Mate before Miyo, but it just didn't work well on my computer. Of course, there is always the possibility that I screwed something up during the install. It is a little bit more complicated than installing Miyo. And while I know a little more than the average computer user, I'm by no means an expert (as I'm sure all on the forum can tell). Plus I've only been using Linux for a couple of years now.

Miyo works great on my system, and as of right now, I have no plans on searching for another distro. I'm well pleased with Miyo. Having to install Mate (and uninstalling the LMDE and Xfce stuff, as well as Openbox) after going through the Miyo OS install is a bit of a drag, but not a big deal as a Miyo install is very fast. A lot of my post was also for the reason that mate-power-manager has systemd as a dependency, and to me that seems to be a BIG red flag that maybe one day the whole Mate DE won't work on a non-systemd OS. (I'm the type of person that likes to be prepared for any and all possibilities.) The reason I tried Miyo is because I needed an OS based on Devuan because of an app I use that I have the .deb installer file of and I don't think it's available for other Linux distros. In addition to Miyo, I tried Devuan (as already mentioned), Exe Gnu/Linux, and Refracta. I liked Miyo best.

Thanks for the info about SpaceFM allowing 4 panes, but I'm not sure that's what I want (I prefer a traditional layout). I can't really say for sure though, as I'm not quite sure what is meant by "panes." Can you give a screenshot of what you're talking about?

Let me end this post by thanking you for making a great OS, and for all the time you've put in in helping me out here on the forums. I do appreciate it.

So I'm curious,  what DE do you use now?

Thank you MiyoLinux and ivanovnegro. It seems to be working now as it should.

EDIT
There is one weird thing. Now when opening a new window, instead of it immediately appearing, it kind of fades in instead. I think I can live that though.

EDIT #2
I found a line in compton.conf that read fading = true;. I changed it to false and that seems to have taken care of the fade in.

Here's what it reads:

backend = "xrender";
#backend = "glx";

So I take it that I should change it to this . . .?

#backend = "xrender";
backend = "glx";

It is available in Synaptic. If I need to download it, how do use it in place of the others?

FTR, I don't recall having this issue in Jessie. But it could have been that I just missed it then, but I don't think so.

I looked in Synaptic, and compton is installed. I typed "compton" in the terminal, and when I pressed enter, the screen blinked for a split-second, but nothing else showed up in the terminal, not even a new ron@ron:~$. After this (still with the terminal opened), I still get the screen tearing.

EDIT
This is weird. After closing the terminal screen and opening a new one and again typing compton in it, I now get the message that "Another composite manager is already running".