Build issues with checksums


I have set up an unbuntu xenial and trying to build a debian image.
The make process starts with downloading I get repeated checksum errors :
config/functions/build-package:70 Error: Incorrect checksum calculated on downloaded file: got bb258c6b7840659a9471f1617ed6aae1265703849708bbbceb3c4edc40db8703, wanted a58d6dd246c37993f3866300bf4f00568c34d43ac9668e11dc9688f0c926e8cf

when patching the checksum in the package definition file, the next package will also fail…