Hi – It sounds like you are trying to use the same keys that you created for the Woocommerce app for Xeroom. This won’t work unless you manually copy the .cer file that you used to create the keys in Xero into the xeroom\library\certs directory since they are an essential part of the communications keys.
If this still does not work then recreate the Xero keys and try again. If still not then let me know and I will investigate to see why.
Thanks
Pete