Random 500 Internal Server Errors when loading list of images

[peppies]

I have a marketplace site where our page loads up a list of products and their images in pagination (25 or up to 200 thumbnails per page). After every other page, one or sometimes two random images loaded with SLIR will have a 500 internal server error. If I refresh the page, the image loads normally.

I think SLIR is having problems when it tries to load up a list of thumbnails at once, or it's causing problems with the server. This has been going on for years and i just ignored it since it works 99% of the time. Still, there shouldn't any errors if the image exists and there is plenty of memory available on the server.

Any help would be appreciated.

Notes: I've upgraded my version of PHP to 7.0 and SLIR appears to be working just as it did on PHP 5.4. I am using the 2011 version of SLIR (I believe version 2.0b4?). I attempted to download and use the current 2014 version on github and it's doesn't work at all, so I reverted back to the 2011 version that works...

Thanks
Kind regards

[peppies]

When a page loads, is it possible that the SLIR script gets called 25-200 times all at once and this causes some kind of crash for 1-2 images every other page load? Maybe there is a way to limit how many requests can be done at one time?