Hey! the solution worked... but only for a minute. I then increased the memory again but this time a few 100s less and it crashed again. Then I tried both solutions again and this time they didn't work. Restart didn't help either. But the first time it worked so what happened now?
but originally when it wasn't crashing it was either around 500 or 600
(scratch disk c)
Scratch space is not memory its storage like ssd or hard disk. If you C: drive is your Boot drive and it does not have at least 100GB free remove it from Photoshop Scratch disk and use other disk's free space for Photoshop Scratch space. You may be able to hold Ctrl+Alt starting Photoshop on Windows 7 it is a shortcut for configuring Photoshop scratch disk. Windows 10 seems to have taker over Ctrl+Alt. or its broken in CC 2019. I have seen Photoshop use over 100GB of scratch space. You do not want Photoshop to fill up your startup disk. Photoshop will fill its first scratch disk before it start to use a second disk.
I can starts Photoshop CS6, CC 2018 and CC 2018 and racer to press and hold Ctrl+Alt and get the Scratch Disk Preferences however not CC 2019
If I keep holding Ctrl+Alt cc 2019 will eventually open but not present the Scratch disk Preferences dialog. So one more CC 2019 bug.