On some servers the image edition library (ImageMagick by default) passes the tests, but fails when used in real conditions. This is a rare case though, but hard to debug.
When it happens, the script simply stops. The user only sees the optimization processing, then stopping after several minutes, only displaying the media's previous state (aka not optimized).
Maybe it is a performance issue but I'm not sure how to determine the reason, to reproduce, and to fix it.
Source.
On some servers the image edition library (ImageMagick by default) passes the tests, but fails when used in real conditions. This is a rare case though, but hard to debug. When it happens, the script simply stops. The user only sees the optimization processing, then stopping after several minutes, only displaying the media's previous state (aka not optimized). Maybe it is a performance issue but I'm not sure how to determine the reason, to reproduce, and to fix it. Source.