When painting on a 16bit color depth canvas the burn filter brush produces green diagonal lines when set to shadows. This also happens when adding the burn filter with the shadows setting to a layer.
Wolthera confirms in https://forum.kde.org/viewtopic.php?f=288&t=142763&p=384152#p384152, so setting status to confirmed/
(I can confirm on Ubuntu 14.04 with Krita 4.0.0-beta1.1.appimage. Checked on a A4 300 ppi 16-bit document. I get "vertical" green stripes though, when using the "Filter > Adjust > Burn" in "Shadow" mode)
Created attachment 115154 [details] KRA file showing the bug, the burn filter is as filter mask here The file contains 2 layers. 1 layer is 8 bit with a burn mask and set to shadow, this layer works and below that layer is another one 16bit with the same filter as mask, it has green stripes.
Git commit e91d0c0ad727123159f263b083755af346baefe9 by Dmitry Kazakov. Committed on 26/09/2018 at 11:00. Pushed by dkazakov into branch 'master'. Fix Burn filter to work in 16-bit color space M +1 -1 plugins/color/colorspaceextensions/kis_burnshadows_adjustment.cpp https://commits.kde.org/krita/e91d0c0ad727123159f263b083755af346baefe9
Git commit 2d6eaf1f6cecc1eebe6764d7dd3a5451a0625026 by Dmitry Kazakov. Committed on 26/09/2018 at 11:36. Pushed by dkazakov into branch 'krita/4.1'. Fix Burn filter to work in 16-bit color space M +1 -1 plugins/color/colorspaceextensions/kis_burnshadows_adjustment.cpp https://commits.kde.org/krita/2d6eaf1f6cecc1eebe6764d7dd3a5451a0625026