You could shut off SmartPaste for that language and see if the result is the same.
I turned off SmartPaste but it still won't let me paste spaces.
I'm seeing this in all dialog boxes and on the SE command line. Open Options and try to paste spaces in the search box. Normally at this point I'd think it was a Windows problem but I can paste spaces in dialog boxes in other programs.
I think I forgot to post my program info.
SlickEdit Pro 2024 (v29.0.3.0 64-bit Qt5)
Serial number: [redacted]
Licensed number of users: Single user
License file: C:\ProgramData\slickedit\29\slickedit.lic
Build Date: June 18, 2025
Emulation: CodeWright
OS: Windows 11 x64
OS Version: 11.00.0
Memory: 45% Load, 29251MB/64980MB Physical, 33508MB/69076MB Page File, 5233MB/134217727MB Virtual
Shell Information: C:\WINDOWS\system32\cmd.exe /q
Screen Size: 1920 x 1080 (0 0 1920 1080), 3840 x 2160 (1005 -2160 3200 1800), 3840 x 2160 (-2835 -2160 3200 1800)
Project Type: Gnuc
Language: . (Plain Text)
Encoding: ACP (1252)
Installation Directory: C:\Program Files\SlickEdit Pro 29.0.3\ (non-removable drive,NTFS,736911MB free)
Configuration Directory: C:\Users\RickyBennett\AppData\Local\SlickEdit\29.0.3\ (non-removable drive,NTFS,736911MB free)
Migrated from: C:\Users\RickyBennett\AppData\Local\SlickEdit\28.0.0\
Imported options from: 29.0.1.0
Spill File: C:\Users\RickyBennett\AppData\Local\Temp\slkspill.RickyBennett.25944 (non-removable drive,NTFS,736911MB free)