So, when someone gets creator's block, it's not that their skill goes away, far from it. What this means is that even if you cannot apply your skills and knowledge to the track you are working on, at this particular session, it doesn't mean you can't be productive.
One of the best ways to get out of creator's block is to start making new patches and presets for your instruments. You may stumble across the sound you were looking for as you go! Remember to save those patches for future sessions, and don't worry if you find yourself developing a sound that doesn't fit with the current track - you can always find a way to include it in future tracks, saving you time and effort. Just think how big a preset pack you can make if you keep getting creator's block regularly. The more sounds you have, the better chance of progressing in the song.
Another thing to consider is going out and find / record samples. These could be the necessary sounds to bring you past the mental block. Try spending half an hour sorting through your old, unfinished projects and rendering any sounds you really like. Even if they are unfinished, doesn't mean there's not some salvageable audio. Try and incorporate some of these sounds into your track - you clearly liked them enough in the past to include them in a project! Again, like with the presets, if you build a large sample pack over time, you'll be able to avoid creator's block much more easily.
Try completely chopping up the track you are stuck on. Randomly mute any one track and try recording a new part for it (save originals). Figure which is best and move on from there. Try reversing small parts of melodies and rearranging parts to make completely new melodies. This is great if you are a fan of the performer in Massive, record a part and then chop it up so you have endless possibilities and "micro-remixes" of sounds within the song. Perhaps one of these slight changes will inspire a new idea.
Find a few song stems from songs in the same key and tempo and incorporate random parts into the track, see what it adds and then record from there. Now remove the stem sample. What's great about this, is it allows you to essentially jam over a sample that is successful, the notes you then play can keep some of the essence of this sample, but when you remove it it is purely your own work.