Uploading Form error

Hi

I am having problems with transaction SFP (form builder)

I go to UTILITIES and select DOWNLOAD FORM.

I get a file SFPF_*.XML generated.

When I try to upload it (UTILITIES and select UPLOAD FORM) (the goal is to a different enviroment but I tried on the same as well) I get the below error:

"Error occurred when uploading file (unknown file format)

Message no. FPUIFB068"

Any clues why this is happening?

Regards

/V