just happened again. under different circumstances. only 3 layers. 200 ppi ish. a4 size. Trying to cancel inner shadow tool.
Application paint.net 4.0.9 (Final 4.9.5848.30436)
Build Date 05 January 2016
Hardware accelerated rendering (GPU) True
Animations True
DPI 96.00 (1.00x scale)
Language en-US
OS Windows 7 Service Pack 1
.NET Runtime 4.0.30319.42000
Physical Memory 8,157 MB
CPU AMD A8-5600K APU with Radeon HD Graphics
Architecture x64 (64-bit)
Process Mode 64-bit
Speed ~3593 MHz
Cores / Threads 4
Features DEP, SSE, SSE2, SSE3, SSSE3, SSE4_1, SSE4_2, XSAVE
Video Card AMD Radeon R9 200 Series
Dedicated Video RAM 4,075 MB
Dedicated System RAM 0 MB
Shared System RAM 3,822 MB
Vendor ID 0x1002
Device ID 0x6810
Subsystem ID 0xE271174B
Revision 0
LUID 0x0000DDB7
Flags None
Outputs 2