Hard to say without seeing full error details
First thing to check:
You are changing files by reference their position on the list - are you sure your list has that many files?
[0] is first file on the lis, [6] is seventh etc.
If you have a list of files, and you want to rename each, use "for each" loop.
Example, copy and paste into your flow:
Folder.GetFiles Folder: $'''C:\\Users\\yourusername\\Desktop''' FileFilter: $'''*''' IncludeSubfolders: False FailOnAccessDenied: True SortBy1: Folder.SortBy.NoSort SortDescending1: False SortBy2: Folder.SortBy.NoSort SortDescending2: False SortBy3: Folder.SortBy.NoSort SortDescending3: False Files=> Files
LOOP FOREACH CurrentItem IN Files
File.RenameFiles.Rename Files: CurrentItem NewName: $'''newname''' KeepExtension: True IfFileExists: File.IfExists.DoNothing RenamedFiles=> RenamedFiles
END
