Glad you got it sorted. But taking something away doesn’t prove it wasn’t a memory problem.
If I had a glass full to the brim with gin and tonic and then added an ice cube it would overflow. You could say the problem was that I added the ice cube. I would say that since I wanted a large gin and tonic with ice in it the problem was that the glass was too small.
If you added the HTML filter back in and exported using the technique Dan suggested in that link I gave and the export was successful it would more or less prove that the problem was a shortage of memory.