OG Daniel 7:27-28 – ‘until the end of the matter’
Here the Old Greek text probably has either a translation error, or a later copyist error.
It puts a little extra phrase to the end of verse 27, saying the holy ones will rule the kingdom ‘until destruction of the word/matter,’ probably an expression meaning ‘until the end of the matter’ or simply ‘until the end,’ (like when we say ‘until the end of time’).
The Masoretic Text doesn’t say that, but it does have a phrase that sounds very much like it, but it’s not attached to this statement. It’s at the start of the next one, where DaniEl says ‘And this is the end of the matter’.
So this could easily be a silly error in reading the Aramaic, or a later copyist error. It’s not 100% certain. However, the issue doesn’t really matter much as it’s just a throwaway phrase.