Adobe Media Encoder 2020 is not working (This project could not be opened)

I have just downgraded to AE, Media encoder still last version

I am also having this problem as was a coworker.  For what it's worth, the problem started for both of us after installing Boris FX Continuum/Sapphire 2020.  After trying to reinstall both AE and AME to no avail, he uninstalled the aforementioned plugins and that solved the issue for him.  I opted to revert to previous versions of AE and AME (16.1.3 and 13.1.5, respectively) for the time being. 

MacBookPro16,1 / 8-Core Intel Core i9 / 64 GB RAM / Catalina 10.15.4 / After Effects 17.0.6 / AME 14.1)

I am having the same issue. It occurred in the middle of a critical project for an awards entry. I'm only getting to these now, because I could not afford to stop and revert, I had to keep going with the versions/edits I had already from the latest releases.

Downgrading is not acceptable, b/c it removes critical updates to software and plugins used to make the project.  This wasn't a problem prior.

For me, I am getting: Cannot Read From Source.

I have been using Adobe for 20 years. Trust me, I went down the list of the usual suspects: from cache to prefs to drivers on Win 10. The same projects which were rendering fine before the update, now have this problem -- so I know it is the software. Having to render from AE and then compress from AME is a major productivity killer.

Further, having to render from AE without any of the other CoDec support, it used to be the same across AE, Pr, and later also, AME is also a time-suck. I don't understand why the same CoDecs are not in all the video apps. This means I also have to export twice. Once from AE to get a video file or sequence, then compress that into h.264. Despite having an RTX 2080 with 8GB of VRAM, AME still uses the CPU to render (WTF?!), despite explicity requesting it use the card. So, it's also reducing productivity by not working as instructed. Yes, the software and the OS can "see" the card, it's strictly an Adobe programming issue.

This needs an update, ASAP.

i was have same problem. After update to win10 media encoder was broken. I try everything what you say guys, but i fix it by update my cuda driver. Meybe it help someone 

I had the same issue, downgrading also solved my problems. I hope this gets fixed soon.

Same prome here. 

I find it very frustrating that Adobe don't do what they can to push out a release a patch as quickly as possible, when AME at its current state on Windows is actually completely unusable. It can't really be any worse than it is. 

acutally i don't know what happend.
but i contacted the adobe support - and told them what my issue is. while i was communicating with them i tried again - went to AE ---> send compostions to AME - and it worked. suddenly.
but i tried to import the .aep File into premiere (opened premiere --> import --> import .aep file - ---> connection to dynamic server failed. so i told them that this doesn't work.

the support told me something i should rename my - Premiere Pro folder at  Documents --> Adobe to Premiere Pro_old and the dynamic server folder as well into dynamic server folder_old, but there was no dynamic server folder there so i just renamed the premiere pro folder.

and the folders at creative cloud files - there was the dynamic folder in so i went there and renamed both folder - dynamic link server folder and the premiere pro folder.

then i opened premiere pro and tried to import the .aep file - didn't work. 
so adobe support told me to do so:

open AE - create new composition - save it --> open premiere pro try to import it - WORKED but to import my  old aep.file  into premiere pro didn't work. --> go to AE - import the old composition (from my old .aep file) into AEs new created project and new comp.. --> go back to premiere Pro - import composition and it WORKED trough the new .aep. file.

i hope you did understand a little bit of this what i just wrote and i hope it will help you.

Br Stipe

Could the problem be that dynamic link is a 32-bit program? I dont know a lot about software, but I've updated to MacOS Catalina, and I think it doesnt support 32-bit software anymore. Here is an image from my system report 

I am having the same issue! I thought maybe it was a Catalina issue, as I've very recently upgraded to Catalani and updated to 14.1 at the same time.

I used to be able to update in AME 2020, but now I can ONLY connect to project in 2019 AME which is 13.1.5. None of the 14.x.x versions work.

I have tried following many other answers but downgrading was the only thing that worked.