Speculating. If your iproute2 package crossed the 4.10.0 boundary, then "ip route get" will show uid, which pptp-linux will not handle as it parses the output carelessly.
Upstream pptp-linux patch is 7d9a428 ("Remove uid from ip route get
output.").
https://github.com/quozl/pptp/commit/7d9a428a0744b3053767dc2d239f305c86f1fcee
--
James Cameron
http://quozl.netrek.org/
