Trying to install OBM on MAC but its asking for a proxy

This could be the security settings of the latest Java version blocking the https connection.

Please try edit the JVM's "java.security" (/library/Java/JavaVirtualMachines/jdk1.8.0_71.jdk/Contents/Home/jre/lib/security/java.security) to enable MD5 on those MAC client machines to see if this help:

Change the following settings in "java.security":

1.from jdk.certpath.disabledAlgorithms=MD2, MD5, RSA keySize< 1024
to
jdk.certpath.disabledAlgorithms=MD2, RSA keySize< 1024

and

2.from jdk.tls.disabledAlgorithms=SSLv3, RC4, MD5withRSA, DH keySize< 768
to
jdk.tls.disabledAlgorithms=SSLv3, RC4, DH keySize< 768

Once above implemented kindly apply following.

1. Edit the file "/Applications/OBM\ PRO/custom.xml"
2. Change the line: (**)
protocol="https" hostname="rdr.secure-backuponline.com" port="443"
to:
protocol="http" hostname="direct.secure-backuponline.com" port="80”
3. Save the file