Thanks for your answer @Craige_Hales.
When I open it using the Excel Import Wizard of JMP it works as expected and here is the corresponding source script:
Open(
"$DESKTOP/Test JMP Import/Test.xls",
Worksheets( "Sheet1" ),
Use for all sheets( 1 ),
Concatenate Worksheets( 0 ),
Create Concatenation Column( 0 ),
Worksheet Settings(
1,
Has Column Headers( 1 ),
Number of Rows in Headers( 1 ),
Headers Start on Row( 1 ),
Data Starts on Row( 2 ),
Data Starts on Column( 1 ),
Data Ends on Row( 0 ),
Data Ends on Column( 0 ),
Replicated Spanned Rows( 1 ),
Replicated Spanned Headers( 0 ),
Suppress Hidden Rows( 1 ),
Suppress Hidden Columns( 1 ),
Suppress Empty Columns( 1 ),
Treat as Hierarchy( 0 ),
Multiple Series Stack( 0 ),
Import Cell Colors( 0 ),
Limit Column Detect( 0 ),
Column Separator String( "-" )
)
)
However, it seems that indeed the format file is a bit weird, because I have an Excel warning when I try to open it directly from Excel... And if I try to attach it to this message I have an error as well:
The problem is that I am not the one who created the files at first so I don't know if it is possible to fix that afterwards without having to manually open / save each file