repeated minify error

Since the last version of W3TC, I’ve been getting emails telling me that there’s a minify error:

“Unfortunately, an error occurred while creating the minify cache. Please check your settings to ensure your site is working as intended.”

That is very strange, because we don’t even have minification enabled.

Also – the “support us” popup loads on every page – it won’t go away, even if I enter my email and click to sign up for the mailing list. (I don’t really want to, but would if it would make the pop-up go away.)

What can be done about these glitches?

https://ww.wp.xz.cn/plugins/w3-total-cache/