In most cases where you have trouble with the front-end editing, there are only a few reasons that make mostly problems.
Please check the following problems:
1. Duplicate jQuery integration:
simpleCE comes with it’s own jQuery version, if you also use jQuery in your theme or website it will be included twice and that can cause problems. Make sure that you only use one jQuery file in your website. You can find more details about using jQuery in simpleCE in the developer menu in you backend.
2. Script conflicts:
Sometimes it’s possible that scripts that you use on your website, are not compatible with scripts that simpleCE need to work.
You can find more details about this in the developer menu in your simpleCE installation.