Tidy - Stopping ... File cannot be updated.

From few days I very often have that problem

>"C:\Program Files (x86)\AutoIt3\SciTE\AutoIt3Wrapper\AutoIt3Wrapper.exe" /prod /in "L:\TOOLs\Macro\____PROGRAM_MANAGER\PROGRAM_MANAGER.au3"

+>13:36:20 Starting AutoIt3Wrapper v.2.1.2.14    Environment(Language:0415  Keyboard:00000415  OS:WIN_7/Service Pack 1  CPU:X64 OS:X64)

>Running Tidy (2.3.0.8)  from:C:\Program Files (x86)\AutoIt3\SciTE\tidy

!> Stopping Tidy process because the input File cannot be updated. Check security/readonly attributes for file:L:\TOOLs\Macro\____PROGRAM_MANAGER\PROGRAM_MANAGER.au3

!>13:36:20 Tidy ended.rc:99

>Exit code: 0    Time: 0.613

This problem is very strange for me because

• I never before have that erorr
• when I push F5 again, again, again then script run after some more attempts
• sometimes it works at first time sometimes after 10 attempts
• I disable AV - this dont take any effect

What is important disc L: is USB PENDRIVE

Do any body have the same problem ?