It's a pretty intractable problem, with several complex tradeoffs viz a viz the permissions issue.
I can't open the program at all (as you can see by the attached screen shot error message appearing before any PS panels fully load) so you can imagine that the menus have not even loaded yet, which is true.
So trying to access the filepath you recommended is impossible at this nanosecond.
There's no image "attached". You can't show an image if you are accessing the forum through e-mail. Any file attached to an email will just disappear into cyberspace, without anyone ever seeing it.
To embed an image in a post, use the camera icon in the Reply Editor in the forum's web interface using your web browser.
Back to your issue:
You need to trash your Photoshop preferences by holding down Command+Option+Shift as you launch Photoshop until you get a dialog box allowing you to delete your preference settings.