Java Edition:Invalid Supporting Block

Normally only solid or transparent blocks can provide support and connect to fences and walls, but sometimes other blocks also gained these properties too.

Definitions

Cylindrical

These are majority of the blocks, these act like transparent blocks; they can support and connect to everything on the sides but these can only allow certain blocks like snow, pressure plates, buttons and levers on top of them.

Partly Solid

These are alike to normal solid blocks, they supports everything on all normally valid surfaces but cannot be powered using redstone.

Opaque

These are the simplest type, supports everything on all normally valid surfaces and can be powered using redstone.

Intentional Changes

Chest

From their introduction in Indev 0.31 20100124-2119 to Beta 1.9 Prerelease 5 (a 1.0.0 snapshot) chests were completely opaque.

Glass

Glowstone

Since glowstone was added in Alpha 1.2.0 it has changed a lot.

Soul Sand

Hopper Topside

Unintentional Bugs

Hopper Underside

From 17w47a to 19w12b buttons and levers could be placed underneath hoppers.^[5]

End Portal Frame

From 1.4.3 to 15w46a (a 1.9 snapshot) end portals frames were completely opaque.

Banner and Skull

From 17w47a to 17w50a (1.13 snapshots) hanging banners and skulls accidentally became cylindrical supporting blocks.^[6]

Turtle Egg

When turtle eggs were introduced in 18w07a (a 1.13 snapshot) they were considered cylindrical supporting blocks.^[7]

Conduit

When conduits where first added in 18w15a to 18w20a (1.13 snapshots) they were cylindrical supporting blocks.

Bamboo Sapling

When bamboo was first added in 18w43a (a 1.14 snapshot) its sapling were cylindrical supporting blocks.^[8]

Stonecutter

When stonecutters were first added in 18w44a to 18w45a (1.14 snapshots) they were considered a cylindrical supporting block.

Chorus Flower

From 18w48a to 19w12a (1.14 snapshots) chorus flowers became a cylindrical supporting block, and then from 19w12b to 1.20.1 they were promoted to being partly solid.

Lectern

In 19w02a (a 1.14 snapshot) lecterns top face became partly solid allowing snow, buttons and levers to be placed on them.^[9]

Scaffolding

From 19w03a to 19w04b (1.14 snapshots) scaffolding became partly solid.^[10] This was partly recontinued in 19w13a (a 1.14 snapshot) where scaffolding was able to have blocks attach on top again.

Shulker Box

From 19w13a (a 1.14 snapshot) to 19w42a (a 1.15 snapshot) closed shulker boxes would connect to walls, fences, iron bars and glass panes^[11]

Wheat

From 19w41a (a 1.15 snapshot) to 1.15 Pre-Release 2 snow was able to be placed on fully grown wheat.^[12]

Azalea

Warning: Downgrading 

This feature requires downgrading which can result in crashes, data loss, or corruption, and requires specific versions. Follow the page instructions carefully.

Warning: Corruption 

This feature can corrupt the world. Perform at your own risk.

From when they were added in 21w05a to 21w11a (1.17 snapshots) azaleas were cylindrical supporting blocks.^[13] Azalea also supports top side blocks but this is normal and still presently works.

Obtaining

Due to lush caves not existing until 21w10a and not generating in default worlds until 1.18 Experimental Snapshot 1 means you either have to downgrade from 1.18 Experimental Snapshot 1 or regenerate your level.dat in 21w10a as a buffet world with the biome set to lush cave and generate new chunks. Or you could obtain it by bone mealing moss obtained from a wandering trader or shipwrecks in 21w13a.

Either way downgrading is necessary.

Generic Methods

Update Suppression

As with almost every block discontinued feature, most of these can also be created using update suppression. However, update suppression cannot suppress updates in the west direction, so it is impossible to "place" blocks requiring support on the west face of these blocks.

1.12 Transparency

When stairs were changed to allow blocks to be attached to them in 17w15a this accidentally led to many bugs allowing many block configurations.

• From 17w15a to 17w16a~, various blocks became cylindrical supporting blocks allowing torches, redstone torches and snow to be placed on them.^[14]

• In 17w18a various transparent blocks were able to have buttons, lever and for pistons and glass blocks torches.^[15]

• From 17w18a to 1.12-pre2 Transparent blocks became cylindrical support blocks allowing tripwire, ladders and vines to be placed on them.^[16]

• In 1.12-pre3 ladders could be placed on transparent blocks if a solid block was next to it.^[17]

• 

  17w15a Every new accidental cylindrical supporting blocks
• 

  Every transparent block that could have normally invalid support blocks on them

Note: placing buttons or levers on shulker boxes will crash.

References