Push notifications stuck on "processing"

Some of these notifications and one email are 2-3 weeks old. Stuck on processing and refuse to delete.

I have 16 messages here in total.

I noticed the cause was whenever I tried to pass a document to the createPush method, I get this error. That made sense to me, so when I pass small amount of data, it works

Now, all I just want is for these to go away cos I cannot delete them