Image upload HTTP Error

Try deactivating all plugins. If that resolves the issue, reactivate each one individually until you find the cause.

If that does not resolve the issue, try switching to the default theme for your version of WordPress to rule-out a theme-specific issue (theme functions can interfere like plugins).

@matthew. I only had 3 plugins installed, and I tried deactivating all of them, but that didn’t solve the issue.

I am on the default 2015 theme, with no custom themes installed.

I would suggest that you check out the suggestions in the links below.

https://wordpress.stackexchange.com/questions/59763/how-to-fix-http-error-when-uploading-images
https://themeskills.com/fix-http-error-when-uploading-images-to-wordpress/

The issue seems to have been with nginx proxy.

Setting the setting to this helped:

client_max_body_size 1000m;