Problems when update Template

i use the Template Hair Version 2.4.0 Sparky 2.4.0 and Joomla 3.6.4 on www.hausbau-beratung.com
When i install another Template with Sparky 2.7.9 and install the Plugin Sparky On Save there is the following error displayed

Error displaying the error page: Error decoding JSON data: Control character error, possibly incorrectly encoded: Error decoding JSON data: Control character error, possibly incorrectly encoded

What is to do?

Hello,

It's not possible to install multiple Sparky's on the same Joomla instance. You should have one Sparky template installed and create multiple template styles if you need.

Regards,
Milos