Hi mythusmage, this means that you are using PHP 5.2 or lower.
Unfortunately, we are required to use PHP 5.3 and higher because of some important feature we’re using isn’t compatible with PHP 5.2 🙁
Would you mind checking it out with a plugin like https://wordpress.org/plugins/display-php-version
I’m actually using 5.5 and 5.4 for development. From what I know, this error is caused by anonymous functions. If we fix the anonymous function in toolbar.php the same error would definitely show up since other scripts use them as well.
I hereby grant you permission to repair the error on line 53.
I have created a new branch that contains the fix for that line. Please give this a try: https://github.com/gambitph/Page-Builder-Sandwich/tree/usort-unexpected-function (download the zip from the button on the right side of the page).
If you still encounter a similar error, we can be sure that you are using 5.2 and not 5.5
Before we go further you can verify your PHP version with a plugin like https://wordpress.org/plugins/display-php-version
Actually, we were both wrong; the version is 5.3.29. In any case I’ll wait for the update.
Were you able to try the branch?
I’ll wait for the update.
Then it turns out PHP was set to 5.2. Reset it to 5.4, and that fixed the problem.