The bug
Torches can be placed on top of fences, but not on iron bars or glass panes.
Note
End rods can be placed on iron bars and glass panes.
Linked issues
Comments
Neither client nor server crashed, so there is no crash report to attach.
I did not see a duplicate, but I think this is intended since these blocks are too thin to support a wider torch on top of it.

Confirmed in 19w12b

Still in 19w13a

Still in 19w14a

Affects 19w14b

Still in 1.14 Pre-Release 1

Still in 1.14 Pre-Release 2

Still in 1.14 pre-3, 1.14 pre-4 and 1.14 pre-5

Still in 1.14 Release

Still in 1.14.1 Release

Still in 1.14.2 Pre-Release 1 and 1.14.2 Pre-Release 2
Fixed in 1.14.3-pre3. Lanterns, (redstone) torches, and pressure plates can be placed on top of glass panes, iron bars, and end rods as I tested.
Please attach the crash report (
[minecraft|http://hopper.minecraft.net/help/finding-minecraft-data-folder]/crash-reports/crash-<DATE>-client.txt
), otherwise we can not diagnose this issue.For technical support please use the Mojang Support Center.
-- I am a bot. This action was performed automagically!