I accidentally threw my fishing rod on my farm and it stayed in air. same with rails and other non-solid blocks. I am NOT using any mods (including Optifine etc...). Also it's not MC 1.8.1 I couldn't find MC 1.8.
It's much more recommended to update to the version 1.8.4. This is a minor bug as in 1.8.4, it bounces, but it lands shortly after, depending on the block type.
It's much more recommended to update to the version 1.8.4. This is a minor bug as in 1.8.4, it bounces, but it lands shortly after, depending on the block type.