With the following beta versions (both x64 and x86), when selecting View -> Panels -> Customize Toolbar..., the dialogue appears briefly then disappears:
The dialogue works fine in versions 5.20.502.1 and prior.
NB: this looks to be very similar to issue #600.
Windows 10 Enterprise 1909 x64
Sorry, this is a victim of optimization/refactoring, fix will follow soon...
Feel free to test the BETA version "Notepad3Portable_5.20.504.1_BETA.paf.exe.7z" or higher.
See "Notepad3 BETA-channel access #1129" or here Notepad3Portable_5.20.504.1_BETA.paf.exe.7z
_Note1:_ "Notepad3Portable PAF" can be used in "2 flavors", see with or without extension ".7z".
_Note2:_ If you follow the instructions #1105, you can also update your "Notepad3 Installer version" with the latest BETA version (see #1129).
Your comments and suggestions are welcome... 馃槂
Confirmed fixed in version 5.20.504.1_BETA (and subsequent). Thanks.
Most helpful comment
Sorry, this is a victim of optimization/refactoring, fix will follow soon...
Feel free to test the BETA version "Notepad3Portable_5.20.504.1_BETA.paf.exe.7z" or higher.
See "Notepad3 BETA-channel access #1129" or here Notepad3Portable_5.20.504.1_BETA.paf.exe.7z
_Note1:_ "Notepad3Portable PAF" can be used in "2 flavors", see with or without extension ".7z".
_Note2:_ If you follow the instructions #1105, you can also update your "Notepad3 Installer version" with the latest BETA version (see #1129).
Your comments and suggestions are welcome... 馃槂