python - Django/Wagtail some images upload error 500 -

am using wagtail (django variant cms) in virtualenv, on fastcgi + apache + shared hosting.

when uploading images via built-in wagtail image uploader, images work , compile correctly whilst uploads cause 500 internal server error.

have tried looking pattern in types of images cause error can't spot similarities.

i able upload various jpgs, gifs, pngs, sizes varied 88kb 236kb, largest dimensions 1000px x 950px

the files causing errors variety of jpgs, gifs, pngs. cannot upload bigger 300kb, although files 100kb or less cause 500 error. uploading via django-admin causes same issues.

the images work when upload through sftp , cpanel there's no problem there.

wagtail uses pillow image handling.

i'm not sure begin looking this. pillow or django error?

i'd suspect web server setting limit on request sizes - we've encountered similar things when deploying on nginx, imposes 1 mb limit on requests out-of-the-box. (for nginx, relevant setting client_max_body_size.) if you're seeing plain 500 internal server error page rather django error, suggest error happening @ web server level rather within django... you'll more informative error message if check web server's error log.

one easy check can try upload same files in wagtail's 'documents' area - doesn't kind of processing on files (it stores them), if uploads still failing there, eliminates pillow possibilities.