Tilemap Alphas Breaking

Link to .capx file (required! If link is blocked remove the http and www parts):

drive.google.com/file/d/0BzlFHdrNlKogYTJTQWxtemdIdkE/edit

Steps to reproduce:

1. Play the level. Observe the paths on the ground and how the alphas work and are fine and blend with the grass well.

2. Move the object Ash from the layer BG to any other layer.

3. Play the level again.

Observed result:

The path's alphas mess up any time I do anything with the BG layer. I don't know why. Everything is fine in editor but breaks if you play the level after editing the objects on the layer. It looks like there's an additive effect or something on the object but there are no blend modes or effects on anything.

Please help.

Expected result:

Nothing should happen! The transparency should be fine!

Browsers affected:

Chrome: Yes

Firefox: yes

Internet Explorer: don't know

Operating system & service pack:

Windows 7

Construct 2 version:

158.2

honestly i don't touch beta releases so if this is something known and fixed in a beta then ehhh?

MadameBerry, I think it's an artifact caused by your graphics card. My laptop does the same unless I turn WebGL off and then everything appears ok. With WebGL on or off on my old android phone (in Chrome) it works slowly but appears normal as well.

Sounds like a good excuse to buy a new computer!

Yknow that would explain it...

Though turning off WebGL creates seams on all my tiles... I think I'll just deal with the artifacts for now and sob a bunch. I really wish I could get a new computer right now.

Though I don't understand why it would only do it after I move Ash to a different layer.

EDIT: So I just transferred the file onto my friend's computer, which is new and beautiful and makes me jealous. Still breaks when I move Ash out of the background.

I don't get it.

60MB it's quite a big file for bug reports. Did You try recreating this bug in new project using same objects/layers?

I can reproduce, but there are hundreds of events and objects, so it's very difficult to prove it's a bug in Construct 2 and not some logic in your project that changes layer or object effects depending on the layer the Ash object is on. As per the guidelines please provide a minimal project using the fewest objects and events possible to prove it's a problem with Construct 2.

Deleted everything. All objects, all events, except Ash, the three ground tilemaps (I don't know if the issue is layering tilemaps like I am, but if it is I don't know what Ash has to do with it), and the two layers BG and Play.

Still does it.

For the record, there were no events associated with layering or effects on the object Ash to begin with. It was just an object that spawns, waits a second, and then despawns. I just like to keep objects on the layers they're "supposed" to be on, and I happened to notice that the initial instance was on the background layer, went to change it, and everything broke.

Link to capx: drive.google.com/file/d/0BzlFHdrNlKogYTJTQWxtemdIdkE/edit

(Will also update the original post)

Thanks, I eventually tracked this down to a bug in the WebGL renderer. It should be fixed for the next build.