I have the same problem.
My transaction https://blockchain.info/tx/d20483e4540ede66acacebfd1a50fca41d7b8749a163f95b2c5aea666429fad3 is stuck and shows in Electrum 2.8.2 as LOW FEE.
"Child pays for parent" option does not work.
Nor does ViaBTC transaction accelerator: "Transaction does not exist".
When I use https://blockchain.info/pushtx
I get the message: Error Parsing Transaction

What is going on?