ADDITIONAL SYSTEM INFORMATION :
jdk 10.0.1,
Linux 4.4.0-121-generic #145~14.04.1-Ubuntu SMP Mon Apr 16 18:40:43 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux


A DESCRIPTION OF THE PROBLEM :
A bad http header in a GET to retried the jar for a webstart app causes the web server to return HTTP 400 error.
the bad header is (captured via wireshark):
If-Modified-Since: Sun, 07 Dec 3163292 06:58:08 GMT



STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Install 10.0.1, try to launch app with javaws from the command line:
javaws http://server/path/app.jnlp

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
should launch.
ACTUAL -
fails with web server error (400 bad request).

CUSTOMER SUBMITTED WORKAROUND :
none known.

FREQUENCY : always