Thank you for trying my suggestions.
I reverted to PHP 8.0 but nothing changed.
This rules out a PHP version problem. (There are no known issues with Showkase v1.7.6 under PHP 8.0.)
2) I switched to Basic Upload and uploaded a small file successfully and got a green triangle. I then clicked the Images tab to delete the test image, but no images were listed.
That's odd but thanks for trying. I can't think of why this might be at the moment but at least we have this information that we can come back to if necessary.
3) I ran the compatibility test successfully just before I installed Showkase
Presumably all tests pass OK?
4) I switched to debug mode but the Status still just says HTTP error. when I hover over the yellow triangle.
I've never encountered this myself. Unfortunately, the 'HTTP error' is most likely being generated by Plupload (the third-party upload module that Showkase uses) and it's rather generic and doesn't really help us to determine the cause of the problem.
5) I tried setting resizing to default but this did not make any difference.
This rules out the PHP 8.1 / 'thumbnail.php' problem (but changing to PHP 8.0 also rules this out).
Here are some more things to check and try:
(1) Make sure that your image filenames do not have any reserved or special characters in them. Try using only alpha-numeric characters (a-z, A-Z, 0-9) in your image filenames.
(2) Are your images rather large (in filesize)? Check your PHP directives post_max_size, upload_max_filesize and memory_limit to make sure that they are not set too low. Please check in with your web host if you are unsure where your PHP directives are set. (They might be set in a 'php.ini' file or you might be able to set them from within your hosting account's online control panel.)
Check out the description of post_max_size in the PHP documentation: https://www.php.net/manual/en/ini.core. … t-max-size
Here's a quote from the docs which might help you set these values:
Sets max size of post data allowed. This setting also affects file upload. To upload large files, this value must be larger than upload_max_filesize. Generally speaking, memory_limit should be larger than post_max_size.
The current PHP default values for post_max-size, upload_max_filesize and memory_limit are 8M, 2M and 128M respectively. Your web host might set other values as their own defaults.
Whatever your own current values are, try doubling them all (or even quadrupling them if they seem very low).
(3) Check your hosting account's control panel to see if there are any security modules installed which might be restricting the upload of images. Also, check any '.htaccess' files that you may be using to see if there are any entries there which might be causing problems.
Showkase works out-of-the-box on most web servers without any tweaking. Unfortunately, it appears that your web server might be a little too restrictive (at least at the moment) to allow Showkase to function correctly and fully.
I'll keep my fingers crossed that one of these new suggestions will point you in the right direction and that you will be able to resolve your problem.
As before, please let me know how you get on.