futtta on "[Plugin: Autoptimize] error_log"

Hi Ben52;
Well, there were no changes in autoptimizeCache.php between 1.7.x and 1.8, so I'm glad to be able to write this is not a regression ;-)

Regarding the actual error; the line is

file_put_contents($this->cachedir.$this->filename,$code);

which is pretty straightforward PHP that just writes the aggregated CSS (in $code) to cache/autoptimize ($this->cachedir) + autoptimize_<md5hash>.css ($this-> filename).

The only logical explanation for the error-message is that PHP could not write to the filesystem at that moment. I'm afraid there's nothing much I can do at that point.

frank