All gui actions/events/conditions have now displayed names inside triggerdata.txt which is new, hence your old file won't have it. It previously was taken from triggerstrings.txt, but currently not.
If you have custom GUI that you wana keep you have to update your custom triggerdata.txt to the new format including the Displayed Name and Parameters
Why do my triggers look like this?.
Depending how big your additionas are, it might be faster to extract the current one from the game and add your custom ones again, so you won't have to update Blizzard's GUI.
In case you don't want that custom GUI you might disable it for now. Maybe rename the files by adding "not" as first word.
But somehow I would wait with updating the file. The Editor uses no translated texts for non english users right now, hence that file might change again in some patches.