In previous snapshots, we could use open ranges in the "execute if score matches" conditionals. For instance, we could do "execute if score @s Value matches 4.." to check if the score is 4 or higher, or "matches ..3" to check if it's 3 or lower. Or we could use just a number to check for exactly that number, like "if score @s Value matches 5" to check that it's exactly 5.
But now in 18w07b (and I think it was the case in 07a as well), trying to use either open-ended ranges or single numbers both lead to a syntax error and the command fails. You have to use ranges with both a minimum and maximum to get it to work, meaning for exact numbers you need to do something like "matches 5..5", which is weird, and for ranges, you have to have some kind of max cap or min cap hardcoded. Neither is optimal, and it's a loss of functionality from the previous snapshots.
MC-124896 Testing for a score of x or a minimum of x doesn't work in execute if/unless score