**[BUG]** Knife: Unhandled Exception Caught: Exception caught

[dreamparacite]

Issue:

I was making some knife cuts to try and match the knuckle topology from this reference, after a few cuts I got the error message.

How to Reproduce: Between the edge loops on the finger where the knuckle would be, use the knife tool to cut a square into the middle of the edge loop. The error occurred before I could cut the diagonal cuts connecting the middle square to the corner vertices.

Automatically Generated Info

Environment:

- RetopoFlow: 3.2.5
- CG Cookie built
- Blender: 3.00.0 master 2021-12-02
- Platform: Windows, 10, 10.0.19043, AMD64, Intel64 Family 6 Model 158 Stepping 13, GenuineIntel
- GPU: NVIDIA Corporation, NVIDIA GeForce RTX 2080 Ti/PCIe/SSE2, 4.5.0 NVIDIA 497.29, (no shader version)
- Timestamp: 2022-01-14 08:35:54.726211
- Undo: insert, insert, insert, insert, insert, select all, slide edge loop/strip, insert edge loop, insert, insert

Error Hash: fe59243c687f0132d13819c4367cdd3b

Trace:

- EXCEPTION (<class 'ReferenceError'>): BMesh data of type BMVert has been removed
-     C:\Users\KarlLocal\AppData\Roaming\Blender Foundation\Blender\3.0\scripts\addons\RetopoFlow\retopoflow\rfmesh\rfmesh_wrapper.py
- 000 0174:co() self.bmelem.co = co
-     C:\Users\KarlLocal\AppData\Roaming\Blender Foundation\Blender\3.0\scripts\addons\RetopoFlow\retopoflow\rf\rf_target.py
- 001 0561:set2D_vert() vert.co = xyz
-     C:\Users\KarlLocal\AppData\Roaming\Blender Foundation\Blender\3.0\scripts\addons\RetopoFlow\retopoflow\rftool_knife\knife.py
- 002 0527:modal_move() set2D_vert(bmv, xy1)
-     .../common\fsm.py
- 003 0169:wrapped() return fn(*args, **kwargs)

[vxlcoder]

Thanks for the report, @dreamparacite.

I was not able to reproduce your bug, but I added some code that should prevent that from happening again. Please do let us know if you run into this bug again.

you can test it out by using the Updater system (docs) to checkout commit 88a99d4, but we will be posting up an official release soon.

happy retopo'ing!