Did you try to disable the GPU?
Preferences > Performance > Uncheck Use Graphics Processor.
No. What would that do exactly?
It stops Lightroom using the graphics processing unit in your video card, and it will most likely cure the problem with the blue image with an X. You can try updating your graphics driver and see if that allows you to use the GPU.
If not, it's no big deal, you will only get improved performance if you have a 4 or 5k monitor.
See also GPU notes for Lightroom CC (2015)
When I click a custom brush I made it then switches to another.
Do you mean the A and B brushes in the Adjustment brush panel?
They work as expected for me, but there is a possibility that this can also be linked to the GPU.
I keep replying to this and it keeps getting deleted! Please confirm this reply stays.
I have never used this menu, but it seems that if you have made a custom brush, you will have to save it as a preset, and it looks like you haven't saved any presets.
Adjust the sliders the way you want them, and then choose Save current settings as new preset.
disabling the GPU does not help. Its makes Lightroom even slower.
Does it stop the crashing and the image displaying blue with an X?
Are you on Mac or Windows?
I couldn't handle how slow Lightroom was running with the GPU disabled so I couldn't complete a full day without it. The blue square did not appear but that error is completely random. I could not predict when it may happen next. Today is appeared twice within one hour, it has never done that before. I need the GPU turned on.
I am surprised to hear you never use the custom brush menu. they are extremely useful when you are editing the same type of photos each day. I have over 13 custom brushes which are saved within Lightroom.
* I am using a brand new Mac
Updating the graphics driver might fix the crashing/blue image.
On Windows this is easily done, but since you're on a Mac, I believe that driver updates are only done through OS updates.
Maybe another Mac user can say something more about this.
See this page for more info on the GPU: Adobe Lightroom GPU Troubleshooting and FAQ
I have over 13 custom brushes which are saved within Lightroom.
Maybe I'm missing something, but the screenshot of your brush menu looks exactly like mine, with no custom brushes (presets).
This Mac and all of its hardware is about 90 days old. I am not an expert on a Mac but I don't think I should be having any issues on a new computer.
I know the photo of the brushes is just something I grabbed off of Google images. The image is not the point. I wanted to show you the area where I choose a brush and every single time it jumps to another.
I have been talking to you in this forum for over two weeks and my issues are still not resolved. Is there someone I could talk to on the phone at Adobe? I assume others have these issues, will they ever be corrected in an update? This issues affect the speed of my workflow each day.
Sorry that i haven't replied earlier, but I was hoping that a Mac user might reply, and give you some advice. but that hasn't happened.
As for your GPU problem, I have no idea how often the Mac OS is updated, but that is apparently the only way to update the graphics driver. And having a computer that is 90 days old doesn't guarantee that the graphics driver is up to date.
Posting your system info might provide a clue as to why the GPU has to be unchecked.
In Lightroom, go to Help > System Info, click the Copy button, then paste it into a post here.
I have not been able to replicate your problem with the brush presets.
Resetting preferences might fix it, to do so, press Option+Shift immediately after clicking the shortcut to launch LR, then click Yes in the confirmation dialog.
If you cannot make this dialog appear, with Lightroom closed, use the Finder, and navigate to /Users/[username]/Library/Preferences/com.adobe.Lightroom6.plist
Delete the Lightroom6.plist file, then restart your computer, and launch Lightroom.
Here's a link to chat with Adobe, as far as I know, there is no phone support.
For all I know, the screenshot you posted may contain sufficient information (I am no expert on hardware), but it would be best if you pasted the entire contents of the System info dialog here.
But I can see that you need to work with the GPU enabled, your monitor is almost 6000 pixels across.
I guess I could reset all my brushes but that would delete all custom brushes I would have to re-save them all.
Resetting preferences will not delete your custom brushes, if that's what you mean.
There are two issues here. You have some sort of graphics card related issue once every week or so where you see a blue X. My guess would be that this is a memory leak somewhere that overloads the system. This would not be strange with a system with such a gigantic (5K) monitor. Do you quit Lightroom once in a while or restart the machine? That might alleviate it. Lightroom regularly has some memory leak issues that lead to slow down behavior and even lock ups. They were really common at early versions of Lightroom 6/CC. You absolutely want to enable the graphic card acceleration on this machine btw. It will be pretty unusable without.
The second issue of the brush selection flipping sounds like an interface bug I see sometimes with popup choices not holding the first time. I never use custom brushes so I have never tried it on a custom brush selection but I do see it on the profile popup for example.
I do restart when I have this issue but it always comes back.