It is similar to the writer's block.
I cant come up with creative idea at all for the moment. I have a lot of creative works to be done but I couldnt even design a simple 2 inches x 3.5 inches card. I usually capable of doing that in 5 minutes. JUST IMAGINE HOW SEVERE MY BLOCK IS NOW!
Let alone designing a whole booklet packed with infographics and artworks for two programmes. Both are due today.
My last severe designer's block was back in 2006. Long time ago. I still remember, I took quite some times to recover.