Using MultiMC. The result is the same whether downloading the zip file from Curse website and installing via import from zip, or using the create new instance feature with MultiMC. Resolving mod ID's takes for ever, then downloading mods fails at like 90% with "Job 'Mod download' failed to process:". I can download and install ver 3.6 no problem.

5hrs later it worked. Issue can probably be closed.