Site Won't Process Uploaded Photos

Starting yesterday I cannot process images. I upload them using ftp.   Those that I've already uploaded will not process.
Page just says it's processing and not to leave the page, but the rest of the page is blank. 

I uploaded a folder with 5 subfolders, about 900 photos total, each about 200kb (small photos)

My php settings are good. It's a pretty beefy server as well. 
Upload Max File Size32M
Memory Limit512M
POST Max Size32M
File permissions and ownership all look good.   
I'm not sure where to look next...  any suggestions?

The program has worked well in the past(on this same server), so I didn't want to upgrade sytist (4.6) yet -- until after my big Rally.  

thanks for any help,
Randy

So we always find the problems AFTER we contact Tim for help.  lol   
We did have simple corrupted files that was causing the issue.   Grrr...   
Thanks Tim!  :)

I'm still having the problem...  even after removing the photos in question.  

Is there a way to allow sytist to use more server resources?  

We're having the same issue! Any update?

This is the latest entry into the error log: 

And the reply from my server's IT folks at liquidweb.   (Hope I'm not sending irrelevant info...)

64.179.158.102 - - [29/Jul/2024:10:27:51 -0400] "GET /sy-admin/process-ftp-upload.php?date_id=1320&sub_id=2086&folder=bob&sub_folder=%2F07-28-2024%2F09.31am-10.30am&discard_dups=0&check_rotate=0&pic_category=&pic_client=0&watermark_photos=1&logo_photos=0&wm_images_file=sy-photos%2Fwatermarks%2Ftracks-83wm.png&wm_logo_file=sy-photos%2Fwatermarks%2F83-logo-200.png&wm_images_location=top&wm_add_logo_location=bleft&discard_original=1&no_meta=1

HTTP/2.0" 500 337
"https://photos.sturgis.com/sy-admin/index.php?do=news&action=addDate&date_id=1320"  
"Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/126.0.0.0 Safari/537.36"

64.179.158.102 - - [29/Jul/2024:10:28:13 -0400] "GET /sy-admin/process-ftp-upload.php?date_id=1320&sub_id=2086&folder=bob&sub_folder=%2F07-28-2024%2F09.31am-10.30am&discard_dups=0&check_rotate=0&pic_category=&pic_client=0&watermark_photos=1&logo_photos=0&wm_images_file=sy-photos%2Fwatermarks%2Ftracks-83wm.png&wm_logo_file=sy-photos%2Fwatermarks%2F83-logo-200.png&wm_images_location=top&wm_add_logo_location=bleft&discard_original=1&no_meta=1

HTTP/2.0" 500 337
"Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/126.0.0.0 Safari/537.36"

These 500 statuses however were not accompanied by any other log receiving lines to help diagnose the issue.

I've inferred from the GET request the software might be working with the files within /home/photos/public_html/sy-upload/bob/07-28-2024/09.31am-10.30am or /home/photos/public_html/upload/bob/07-28-2024/09.31am-10.30am, but this is about as far as I can understand without more details on how the code operates and on what step the code stopped exactly. For those details it is likely best to defer to the developers troubleshooting.

If those two lines from the sites access log are related to the issue, this is not related to ModSecurity. There were no lines wrote to the Apache error_log today for that IP and relating to ModSecurity.

Embarrassed to say - this was all user (me) error.   Multiple corrupted files.   Once I examined EVERY photo, I found 2 more that I had missed my first time through.