GrantSP

The ONLY way MO2 will have any impact on your MO1 install is if you told MO2 to use the exact same profile(s) as used by MO1. There are no other mechanisms in which either MO can "talk" with each other and possibly mess things up for the other. There are no registry settings or anything system wide that either tool uses that may have become mixed up. All of the settings that determine what MO (1 or 2) does with your mods are just text files stored in the folders in your MO profiles folder.

The reason the install process is failing is, as @GSDFan instructs, the downloads from any other servers are not complete but most likely they are 0Kb long, thus MO2 cannot do anything with them.

Create a new profile, or switch to another one if you have it, and enable just one additional mod and let's see that set of logs. This doesn't make any sense as you say both MO1 and MO2 yield the same result. This indicates to me that there is no fault with the code, but rather either an error in that specific profile or you are in fact missing those DLC. However as you say you can run the game from Steam and they appear that would seem unlikely.

GamerPoets has a series of videos describing MO2 in detail. There is a section in one of them showing how easy it is to migrate from MO1 to MO2.

Please read the pinned topics before posting. https://forum.step-project.com/topic/13336-mo-cant-connect-to-nexus/

Yes there are a couple of ways to do it. From within the MO2 UI you just open the "Information" dialogue and on the 'Nexus Info' tab change the game via the dropdown menu labelled "Source game". Or if you want to you can change the entry in each "meta.ini" file in each installed mod folder in MO2's mods folder. The entry is: gameName=Skyrim for Skyrim and it is: gameName=skyrimse for Skyrim Special Edition. You could do a mass edit with a tool like Notepad++. It has the ability to search through all files including sub-folders and make the change in each.

I see your report there and I'll respond in Discord.

Assuming your Skyrim install is not a crack, and assuming you have all the DLC installed all you need do is start MO and it will see all the files for the vanilla game. Now if the above is correct, to test just create a new profile and see if you can enable just the base game files and start the game. This will tell us if your current profile is broken somehow. Regardless of whether the game starts or not post the last created USVFS log here.

As I mentioned in your TTW thread your issues are totally unrelated to these changes by Nexus.

Clearly you have not been using MO2 as it is far from a "buggy and unstable mess".

Let's see your MO_interface.log and your INI.

You have MO2 installed into the game folder, it can not be installed there as weird errors result due to recursion of the VFS. Move your MO2 install.

Windows 10 completely broke some of the core functionality of NVSR. You must set the ini to these settings: bHookCriticalSections=0 bHookLightCriticalSections=0 I've added a section in the guide to make mention of this fact.

Perhaps you should acquaint yourself with MO more fully by watching the numerous YouTube videos and ensure you have set it up correctly.

Without your logs and your MO.ini it will be almost impossible to diagnose.