Comment # 2 on bug 1017610 from Richard Bos

Created attachment 708496 [details]
y2log during installation with external DVD station

For the error look for the string TSST, that is part of external DVD station
name:

First encounter, with an unexpected character:
2017-01-04 06:10:21 <1> install(3179) [Ruby] modules/InstURL.rb:160 Using
install URL:
cd:/?devices=/dev/disk/by-id/usb-TSSTcorp_CDDVDW_SE-208AB_RL6X853-0:0

With '%':
017-01-04 06:10:22 <1> install(3179) [Pkg]
Source_Create.cc(createManagedSource):199 Probing source type:
'cd:///%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00?devices=/dev/disk/by-id/usb-TSSTcorp_CDDVDW_SE-208AB_RL6X853-0:0'

Hope this helps to locate the culprit.