If you received a Semplice update please read the following update instructions carefully:
Before updating Semplice, please backup every theme file
you edited from your current theme folder.*
After you update Semplice, please empty your browser cache so you instantly get all the new files for the content editor.
Delete old Semplice folder via FTP or delete the theme from 'Appearance -> Themes' by clicking on theme details in the overview and hit 'Delete'. If you cant see a 'Delete' button please first activate an other theme and then delete Semplice.
Now upload (FTP) or install (WordPress) the updated theme the same way you activated Semplice when you first installed it. You should now have the most recent Semplice version installed.
*Unfortunately all changes you made inside Semplice source code will get over-written with the update described above. In case you changed Semplice code, please only update on your own risk since we're not in control of this specific code. If you haven't edited any source code ignore this.
For more information for developers read here.