New block/item tags don't work in commands

Using the new tags in a command returns the error: java.lang.NullPointerException

I tried again on another computer running Ubuntu and interestingly enough, the error was "Unknown block tag 'demo:test'" for an existing tag and java.lang.NullPointerException for a non-existent tag.

Commands that don't work:

/clear @s #minecraft:wool

/execute if block ~ ~ ~ #minecraft:wool