Cannot upload 17.5 beta2 backup

Dear Community,

today I was able to swap the XG device but I was not able to load the backup configuration saved with the 17.5 beta2 from one SW appliance to another SW appliance.

The trick was to upload a 17.1.MR3 configuration on the new empty XG 17.5 beta, boot the 17.5 with the MR3 configuration.

Uploading 17.5 beta config on an SW appliance with same version does not work. This is the message that comes out.

Is this a bug?