I have updated the tags on this post to increase visibility.
This is a known bug in OpenLab CDS 2.x content management when using Internet Explorer to access the web browser. You can track the status of this defect in the OpenLab CDS Software Status Bulletin (KPR#:73829): https://www.agilent.com/cs/library/support/Patches/SSBs/M84xx.html
To work around this issue you can use a different browser (such as Chrome), or you can also use the 'Save as' function to rename the extension back to .rdl.
Ok I tried it to "download it as zip".
It also worked. Chrome we cant install. But rename the bin file also worked.
I opened the bin file with a text editor.
I could clearly see the XML Structure.
Have a great Weekend
I just saw, that I accidently marked it as Discussion... Sorry