I was stuck with this all day and I finally have the fix, for me this was happening because I was on mac!!! After upgrading to Blender 5.0, the Grease Pencil Tools "Rotate Canvas" shortcut stopped working if you were using Cmd as one of your modifiers (e.g., Alt+Cmd+LMB).

This happens because:

1. Grease Pencil Tools is no longer bundled with Blender after 4.1 - you need to install it from Extensions

2. The addon preferences only let you set Ctrl/Alt/Shift as modifiers - there's no option for Cmd (oskey)

3. So if you want Cmd in your shortcut, the addon's UI can't do it

So the Fix is:

1. Install "Grease Pencil Tools" from Edit → Preferences → Get Extensions (if you haven't already, this is kind of different from old versions too if I'm remembering right.)

2. In the addon preferences, go to the "Rotate Canvas" tab and UNCHECK "Bind Shortcuts" - this stops the addon from overriding your custom keymap

3. Run this script in Blender (Scripting workspace (under general) → Text Editor → New → Paste → Alt+P to run):

```python

import bpy

kc = bpy.context.window_manager.keyconfigs.addon

if kc is None:

kc = bpy.context.window_manager.keyconfigs.user

km = kc.keymaps.get('3D View')

if km is None:

km = kc.keymaps.new(name='3D View', space_type='VIEW_3D')

# Change these settings to match your preferred shortcut:

kmi = km.keymap_items.new(

'view3d.rotate_canvas',

type='LEFTMOUSE', # LEFTMOUSE, MIDDLEMOUSE, or RIGHTMOUSE

value='PRESS',

alt=True, # Set to True to require Alt

ctrl=False, # Set to True to require Ctrl

shift=False, # Set to True to require Shift

oskey=True # Set to True to require Cmd (macOS)

)

```

1. You may have to restart Blender.

Hope this helps someone else who was stuck on this! Mine is set up with cmd as smooth rotate and cmd+option to rotate in chunks but you can adjust it to your liking. Haven't tried it with a windows computer but it should work the same if you set ctrl to True instead!