I have bought Impreza version 3.9.1.
After installing the theme on my website, I installed the addon Slider Revolution without any problems.
Yesterday I got a message regarding an available update for the Slider Revolution plugin.
I wanted to install the new update, but it didn’t work.
I always get a message: "Plugin does not have a valid header."
Can you please help me?
You can try to disable the plugin before updating and activate it from Plugins page not from update page or remove the plugin and install it again (if you have the purchase code).
On the other way, could be a theme/plug-in compatible issue. Better to contact the author for the support