Opening specific file causes Notepad++ to be non-responsive

Description of the Issue

When opening the fairly small (577KB) attached test file TEST.txt (encoded in UTF-16 LE BOM), Notepad++ will become non-responsive for 10-40 seconds, depending on the speed / current load of the system.

Also, closing Notepad++ after the attached file is opened will be somewhat laggy (1-3 seconds).

Steps to Reproduce the Issue

1. Set .txt files to be associated with Notepad++
2. Double-click on the attached file in any file manager to open it in Notepad++

Expected Behavior

Notepad++ to be responsive at all times.

Actual Behavior

Notepad++ non-responsive for 10-40 seconds.

Debug Information

Notepad++ v8.3.3 (32-bit)
Build time : Mar 13 2022 - 17:11:10
Command Line :
Admin mode : OFF
Local Conf mode : ON
Cloud Config : OFF
OS Name : Windows 7 (64-bit)
Plugins : Converter.dll CustomizeToolbar.dll DSpellCheck.dll HexEditor.dll mimeTools.dll NppExport.dll NppQrCode32.dll Remove Duplicate Lines.dll TopMost.dll

Start by opening the attached TEST.txt file in Notepad++ v8.3.3 (32-bit) on the stated Windows 7 setup, following the association and double-click steps. Profile the 10–40 second opening delay and the 1–3 second closing delay; done means the file opens and Notepad++ closes without becoming non-responsive.