Not enough RAM error on opening any document
Hi,
I have been using Photoshop perfectly well for some time and all was going well until the latest Windows 10 update (about a week ago). Suddenly, every time I launch Photoshop, I get the following message:

I was using Photoshop CC 2017, so I thought that updating to 2018 might solve the problem. No such luck.
All my other software, including much hungrier packages like After Effects are unaffected, so I'm not sure why this is happening.
The Windows update was a major one and presumably necessary, so I'm not that eager to roll back to before it if I can avoid it, or at least if I can identify which bit of the update is causing the problem and remove it. (I recently had to remove an Windows update that was interfering with my Wacom tablet).
I saw in one post that you can increase the RAM via the preferences>performance panel, but if I try opening that I get an error saying "an integer between 96 and 8 is required".
I've seen lots of people posting about problems when saving documents, but haven't seen the issue at launch time.
Any help gratefully received.
