Frank Goossens on "[Plugin: Autoptimize] 500 error in WooCommerce Pages, when crawled by GoogleBot"

This is probably caused by jsmin having trouble with one specific file (e.g. some files, if already minified, may cause that error). you could either try to identify that file (by looking at which JS-files are specific for the WooCommerce product pages and excluding them from JS aggregation one by one.

As an alternative easy workaround, you could in wp-content/plugins/autoptimize/classes/autoptimizeScripts.php on line 177 replace

$tmp_jscode = trim(JSMin::minify($this->jscode));

with

@$tmp_jscode = trim(JSMin::minify($this->jscode));

which could surpress the error.

hope this helps,
frank