I think the problem occurs when your themler version that is included in the template is to old.
I have an answer from the Themler team.
Maybe this can also help someone else. It worked fine for me.
For those sites where you just cannot press Edit template button there is a manual fix that allows you to open a template and update it to the latest version.
So here is what you need to do:
1.Open <theme_name>/app/classes/Config.php file
2.Find the following line:
$editor = JRequest::getVar('editor', '');
and insert the following piece of code before it
JHtml::_ ( 'behavior.modal' ); // for SqueezeBox
I think the problem occurs when your themler version that is included in the template is to old.
I have an answer from the Themler team.
Maybe this can also help someone else. It worked fine for me.
For those sites where you just cannot press **Edit template** button there is a manual fix that allows you to open a template and update it to the latest version.
So here is what you need to do:
1.Open <theme_name>/app/classes/Config.php file
2.Find the following line:
$editor = JRequest::getVar('editor', '');
and insert the following piece of code before it
JHtml::_ ( 'behavior.modal' ); // for SqueezeBox