Valid OLC log out of SN-10b

I cannot get a valid OLC flight out of my SN-10b. I purchased the glider a
few months ago, have flown a few flights and all are invalid on OLC.
Prior to download the SN-10 security routine runs and approves the file.
OLC tells me the file error message on his end says Signature Missmatch
and he believes that it is a software issue, recommending me to get the
original software that came with the SN-10, install it and try again.
Unfortunately I don't think I can do that, bought a used glider with the
SN-10 already installed.

All of the SN-10 data transfer utilities I'm using for the SN-10 I
downloaded off the internet, pasted it onto the club laptop that I use to
download. So my question is, does anyone have a similar experience with
their SN-10b? Is it possible that I need to download the software off the
internet onto the actual computer I use for downloading? Will loading the
software differently somehow help? Anything else that it might be?

Thanks for any help,

Kestrel #33 OZ (yes it flies again)