Something wrong

Hello ??

It s look like this plugin is exactly what im searching for since long time, simple with scheduler and availability

Problem is it s not working ??

When i installed, i had an error when activating, it said No Header

Then from plugin page, i could activated it, but it show nothing in the page where i set it up, just im available and days below with no way to check something hours etc

Could you please help me as im also interested by upgrading the plugin ?
I even might be interested to have it specially tuned for me

Thank you !