Error Establishing a Database Connection

Hi,
I’m using WP Super Cache for about 3 years and it works always very good.
Some days ago I updated to WP 4.6 and today WP Super Cache doesn’t work;
my WP website go offline when I enable plugin and appears a blank page with
“Error Establishing a Database Connection”.

I renamed WP Super Cache folder by FTP and my website start working again.

I tried to disable other plugins also but it’s all OK: Error Establishing a Database Connection appears when WP Super Cache is enabled only.

I tried to reinstall plugin and WP but it doesn’t solve it.

Waiting your reply.

Regards

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