intermittent error 'Call to a member function set_display() on a non-object' on Features admin pages

Are you using memcache? We see the same issue from time to time and that's my best guess.

I am also getting this on occasion, but I'm getting it in Checkout, and any pages that display the shopping cart block.

I can fix it by clearing the cache.

It's inconsistent, but I'll keep my eyes peeled, and dig in if it happens again. I'll post updates if I find any.

Correction: I can fix it by clearing the Views cache. It appears that sometimes that Commerce default Views disappear.

When the error is occurring, they do not show up in the Views admin list. None of the Commerce Views do, so going to any page that tries to use one of them gives this error.

Until we have a reproducible problem here, I'm going to mark this "needs more info." I've never experienced the presenting issue (Views disappearing), so I can't confirm whether or not it's a problem in our modules or another.

I'm not 100% positive but from the looks of it, this is because the wrong name of the display is passed into commerce_cart_block_view(). It should be the display_id of 'default' not 'defaults' which is the human name not the machine name of that view.

So here's a patch.

I get this same error, when using Commerce Coupon 2.x with a % discount. The patch above does not fix this particular problem.

This comment fixed it for me: https://www.drupal.org/node/2173963#comment-8913647

Not sure if #6 is the original issue or not, but that's definitely a typo needing to be fixed. It appears the issue may be in another module, so I'm going to mark this a tentative fixed based on #6 but we can always reopen later if need be.

@rszrama I think I saw it originally in commerce_ajax_cart which I am now a co-maintainer so I'll keep my eye out.

Thanks for the fix and commit mention!

You bet - thanks for the patch. : )