Photoshop CC 2018 can't open file

[itt95416287]

We currently have one Mac that can't open certain files on her machine whereas the other Macs can, I have tried uninstalling Photoshop 2018 and then reinstalled the App again.

The problem keeps happening, also Photoshop is slower than usual on her machine and she has just made me aware this morning Photoshop will only let her open one Tab now compared to multiple before.

I have adjusted the mac to use 75% of Computers Ram compared to the previously set 70% any ideas on how to resolve the two above problems?

[itt95416287]

A little more info on this, the problem usually occurs in the morning and is not file size related. Even copying them to desktop has no impact.

The user always reports that come the afternoon, she can start opening files again.