It was just an old PHP version. change 5.3 to 5.6 . thanks a lot @alinawaz and @drosendo.
You have save a whale life.
Happy cheers.
Hi David.
I might be experiencing the same thing.
I can’t view the single product page due to the svi pages are gone. This happens when I activate svi. Is the plugin using cache?
I hope I can get a reply soon.
Thank you.