Corona materials not showing in viewport?

[Jpjapers]

Ive been having an issue for quote some time whereby if a file has a corona material on it, the object often displays invisible. Its still selectable but i have to cycle through the viewport display modes until i find one that it displays in. It never works in perspective mode with default shading but usually works in faceted mode. Only seems to happen with bitmap textures and it happens with both standard and corona bitmaps.  If i switch to art renderer and apply a physical material with a bitmap, it shows fine which makes me think it probably isnt a gpu or nitrous issue?

Any ideas?

I can send a file if needed.

[maru]

Please send a file with a sample texture like this included.
btw next time there is no need to ask if you should send a file, it's always useful, so it's better to send a file than not to do it ;)

[Jpjapers]

Please send a file with a sample texture like this included.
btw next time there is no need to ask if you should send a file, it's always useful, so it's better to send a file than not to do it ;)

Attached, Currently on the lights have corona mats. Attached a pic of how its displaying in my viewport and how it should be showing.

[Jpjapers]

Merging the offending geometry into a new file with just geometry checked in the merge dialog seems to fix the issue