Split Automatically option is not in drop-down

[Rosgrana]

First, my apologies if this is a stupid question, in the wrong place or has already been answered 97 times - I did search and couldn't find it.

I've used Wavepad in the past, but recently downloaded it to a new PC, and when I try to split a file I've opened, I don't get the "Split Automatically" option in the drop-down, only Split at Cursor, Split at Silences, Split at Bookmarks (greyed out as there aren't any), Split into Component Channels, Split into n equal pieces and Split at Fixed Intervals. Am I missing something obvious, or is it a problem with the file? FWIW, it's huge - over 7 hours.

[DannR]

The option it would appear adding the file then Right-click/Split/Split Automatically, Is the option is not there,  the reason is the long of the file.