If you are using Dataclay's Templater with After Effects 2020, we recommend using 17.0.5 or earlier. There is a bug in 17.0.6 that prevents projects using Templater's plugin from opening correctly in Media Encoder. This is a known issue to Adobe. The fix is already in the latest Beta of AE.
I post this not only for our Templater users, but for anyone using AE 17.0.6 having issues with workflows using Media Encoder as this AE bug could be related.