Hi.
I'm sorry to hear you are still having trouble.
I've split your posts into a separate thread as it looks like your problem is not exactly the same as the original poster's (or, at the very least, requires more troubleshooting).
Could you please confirm which version of Showkase you applied the patch to? You say you were using v1.7.7 but the latest version is v1.7.6. (The patch should be applied to v1.7.6.)
The dynamic property error you reported was due to a deprecation introduced in PHP 8.2 (which you are currently using) but the patch should completely fix this issue.
There is no 'themes.php' within Showkase (as noted in the error message you reported) but there is a file named 'themeset.php' which does, indeed, contain a problem at line 60 which the patch addresses.
It sounds very much like the patch has not been applied correctly.
I'd recommend you try to apply the patch again (no harm in doing it more than once) and make sure that all pre-existing files are overwritten. (Check the date on the 'themeset.php' file afterwards, specifically, with regard to the error you reported.)
The patch does fix the error you reported so, after successfully applying the patch, if the error still occurs, then maybe your web server employs a method of server-side caching whereby older files are still used for a period of time instead of newly uploaded ones. It might be worth checking in with your web host to ask if they have server-side caching active on your web hosting account (and ask if they can disable it).
For reference, here is the link to the post containing the information about the patch: https://showkase.net/forum/viewtopic.php?pid=2368#p2368
... and here is the post containing more information about applying the patch: https://showkase.net/forum/viewtopic.php?pid=2376#p2376
I hope this points you in the right direction.