I'm on Squeak3.7 #5989

While loading Yaxo from squeakmap, an error popup is
opened with a 'Not a GZipped stream'  message.
(opening a debugger show that an error is raised fromGZipReadStream>>on: 
from: to: method)
Have I missed something ?
thanks

GZipReadStream>>
on: aCollection from: firstIndex to: lastIndex
    "Check the header of the GZIP stream."
    | method magic flags length |
    super on: aCollection from: firstIndex to: lastIndex.
    crc _ 16rFFFFFFFF.
    magic _ self nextBits: 16.
    (magic = GZipMagic)
        ifFalse:[^self error:'Not a GZipped stream'].
....