WARN (gpu.shader): OVERLAY_shader_armature_sphere_408 FragShader: 
      | 
    6 | #define GPU_FRAGMENT_SHADER
      |  ^
      | Warning: (#62) enable/warn/disable extension is not found. Extension "GL_ARB_conservative_depth" is not supported

WARN (gpu.shader): OVERLAY_shader_armature_sphere_395 FragShader: 
      | 
    6 | #define GPU_FRAGMENT_SHADER
      |  ^
      | Warning: (#62) enable/warn/disable extension is not found. Extension "GL_ARB_conservative_depth" is not supported

WARN (gpu.shader): OVERLAY_shader_armature_shape_433 GeomShader: 
      | 
    5 | #define OS_WIN
      |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  ^
      | Warning: (#310) Inputs that are integers should be qualified with the interpolation qualifier "flat"

RetopoFlow Options path: C:\Users\User\AppData\Roaming\Blender Foundation\Blender\2.91\scripts\addons\retopoflow-master\RetopoFlow_options.json
ERROR WHILE COMPILING SHADER brushStrokeShader
    Vertex shader failed to compile with the following errors:
    ERROR: error(#271) Explicit version number 120 not supported by GL3 forward compatible context
    ERROR: error(#273) 1 compilation errors.  No code generated
    



====================================================================================================
COULD NOT IMPORT RETOPOFLOW MODULES

Environment:
- RetopoFlow: 2.0.3
- Blender: 2.91.2 master 2021-01-19
- Platform: Windows, 10, 10.0.18362, AMD64, AMD64 Family 21 Model 16 Stepping 1, AuthenticAMD
- GPU: ATI Technologies Inc., AMD Radeon HD 7420G, 4.5.13403 Core Profile/Debug Context 15.201.1501.0, 4.40
- Timestamp: 2021-01-29 18:10:51.668372
- Sys Path:
    C:\Users\User\AppData\Roaming\Blender Foundation\Blender\2.91\scripts\startup
    C:\Program Files\Blender Foundation\Blender 2.91\2.91\scripts\startup
    C:\Program Files\Blender Foundation\Blender 2.91\2.91\scripts\modules
    C:\Program Files\Blender Foundation\Blender 2.91\python37.zip
    C:\Program Files\Blender Foundation\Blender 2.91\2.91\python\DLLs
    C:\Program Files\Blender Foundation\Blender 2.91\2.91\python\lib
    C:\Program Files\Blender Foundation\Blender 2.91
    C:\Program Files\Blender Foundation\Blender 2.91\2.91\python
    C:\Program Files\Blender Foundation\Blender 2.91\2.91\python\lib\site-packages
    C:\Program Files\Blender Foundation\Blender 2.91\2.91\scripts\freestyle\modules
    C:\Program Files\Blender Foundation\Blender 2.91\2.91\scripts\addons\modules
    C:\Users\User\AppData\Roaming\Blender Foundation\Blender\2.91\scripts\addons\modules
    C:\Program Files\Blender Foundation\Blender 2.91\2.91\scripts\addons
    C:\Users\User\AppData\Roaming\Blender Foundation\Blender\2.91\scripts\addons
    C:\Program Files\Blender Foundation\Blender 2.91\2.91\scripts\addons_contrib

Exception: 
Error Hash: 2fb9dfdfc3a3d1a8a567dc5415d2ca9e
Trace:
    EXCEPTION (<class 'AssertionError'>): 
    .../common\shaders.py
    000 0068:shader_compile() assert False
    001 0132:__init__() logv = self.shader_compile(name, self.shaderVert)
    002 0113:load_from_file() return Shader(name, srcVertex, srcFragment, *args, **kwargs)
    003 0333:<module>() brushStrokeShader = Shader.load_from_file('brushStrokeShader', 'brushstroke.glsl', checkErrors=False, bindTo0='vPos')
    .../rfmode\rfwidget_brushstroke.py
    004 0026:<module>() from ..common.shaders import brushStrokeShader
    .../rfmode\rfwidget.py
    005 0036:<module>() from .rfwidget_brushstroke import RFWidget_BrushStroke
    .../rfmode\rftool.py
    006 0036:<module>() from .rfwidget import RFWidget_Default
    .../interface.py
    007 0040:<module>() from .rfmode.rftool import RFTool
    .../__init__.py
    008 0179:<module>() from .interface import (
====================================================================================================



Warning: Add-on 'retopoflow-master' was not upgraded for 2.80, ignoring
Warning: add-on "RetopoFlow": 'wiki_url' in 'bl_info' is deprecated please use 'doc_url' instead!
         C:\Users\User\AppData\Roaming\Blender Foundation\Blender\2.91\scripts\addons\retopoflow-master\__init__.py
addon_utils.disable: retopoflow-master not loaded
Switching to fully guarded memory allocator.
Blender 2.91.2
Build: 2021-01-19 16:25:50 Windows Release
argv[0] = C:\Program Files\Blender Foundation\Blender 2.91\\blender
argv[1] = --debug
argv[2] = --debug-gpu
argv[3] = --debug-gpu-force-workarounds
argv[4] = --python-expr
argv[5] = import bpy; bpy.ops.wm.sysinfo(filepath=r'C:\Users\User\AppData\Local\Temp\blender\debug_logs\blender_system_info.txt')
Read prefs: C:\Users\User\AppData\Roaming\Blender Foundation\Blender\2.91\config\userpref.blend
read file 
  Version 280 sub 39 date unknown hash unknown

GL: Forcing workaround usage and disabling extensions.
    OpenGL identification strings
    vendor: ATI Technologies Inc.
    renderer: AMD Radeon HD 7420G
    version: 4.5.13403 Core Profile/Debug Context 15.201.1501.0

found bundled python: C:\Program Files\Blender Foundation\Blender 2.91\2.91\python
Writing userprefs: 'C:\Users\User\AppData\Roaming\Blender Foundation\Blender\2.91\config\userpref.blend' ok
Saved session recovery to 'C:\Users\User\AppData\Local\Temp\quit.blend'

Blender quit
Press any key to exit . . .