Disabling add-ins in the next step. In review of the journal, these lines stood out, but you should disable stuff like PnID modeler, BIM Interoperability Tools, and the like as well:
’ 0:< API_SUCCESS { Starting External Application: Precast for Revit, Class: Adsk.RPCA.Core.PrecastStartup, Vendor : RPCA(Autodesk, www.autodesk.com), Assembly: Autodesk.Precast.Application.dll }
’ 0:< API_SUCCESS { Starting External Application: Enscape 3D, Class: Enscape.Revit.Plugin.EnscapeRevitPlugin, Vendor : Enscape(Enscape GmbH, www.enscape3d.com), Assembly: C:\Users\dwarren\AppData\Local\Programs\Enscape\Bin64\Enscape.Revit.Plugin.2021.dll }
’ 0:< API_SUCCESS { Starting External Application: BluebeamAddin, Class: Bluebeam.BbRevit.RevitAddin, Vendor : BBSI(Bluebeam Revit Plugin), Assembly: C:\Program Files\Bluebeam Software\Bluebeam Revu\20\Pushbutton PDF\Revit\Revit2021\BbRevitAddin2021.dll }
’ 0:< API_SUCCESS { Starting External Application: COINS Section Box App, Class: Coins.Revit.SectionBoxApp.CoinsSectionBoxMenu, Vendor : COIN(COINS, www.coins-global.com), Assembly: .\CoinsSectionBoxApp2021.dll }
’ 0:< API_SUCCESS { Starting External Application: DatasmithRevitExporter, Class: DatasmithRevitExporter.DatasmithRevitApplication, Vendor : com.epicgames(Epic Games, www.epicgames.com), Assembly: DatasmithRevit2021\DatasmithRevit2021.dll }
’ 0:< API_SUCCESS { Starting External Application: Ideate Software, Class: Ideate.RevitExtApp.IdeateSoftwareISW.Application.IdeateSoftwareApplication, Vendor : IDSW(Ideate Software, www.ideatesoftware.com/), Assembly: C:\Program Files\Ideate\Ideate Software 2021\IdeateSoftwareISW.dll }
’ 0:< API_SUCCESS { Starting External Application: IMAGINiT.ClarityClient, Class: ClarityClient.ExternalApp, Vendor : RAND(), Assembly: .\ClarityClient21.dll }
’ 0:< API_SUCCESS { Starting External Application: Lumion LiveSync for Autodesk® Revit® 2021, Class: RevitExporter.LumionPlugin, Vendor : Act3D(Act-3D B.V., https://lumion.com), Assembly: LiveSyncForRevit_2021.dll }
’ 0:< API_SUCCESS { Starting External Application: Newforma Revit Addin, Class: Newforma.Addins.Revit2021.NewformaAddinMain, Vendor : NEWF(Newforma, Inc.), Assembly: c:\Program Files\Newforma\Twelfth Edition\Project Center\NewformaRevitAddin2021.dll }
’ 0:< API_SUCCESS { Registered an external server: Name(Navisworks 2021); VendorId(Autodesk Navisworks); ServerId(68e1934c-ec3b-410c-8c82-434f0cf25446); ServiceId(a9bdf0fd-2632-429e-bc35-50ebc2b824d2) }
’ 0:< API_SUCCESS { Starting External Application: PyRevitLoader, Class: PyRevitLoader.PyRevitLoaderApplication, Vendor : eirannejad(), Assembly: C:\Users\dwarren\AppData\Roaming\pyRevit-Master\bin\engines\IPY277\pyRevitLoader.dll }
’ 0:< API_SUCCESS { Starting External Application: Unifi Revit 2021 AddIn, Class: UnifiLabs.RevitAddIn.UnifiApplication, Vendor : INVL(UNIFI Labs Inc., www.unifilabs.com), Assembly: …\Unifi\UnifiLabs.RevitAddIn2021.dll }
The other possible conflict source would be Dynamo packages - rename your packages folder so that Dynamo would start with no external packages loaded.
Once add-ins are disabled and your Dynamo environment is cleared, restart the system and see if it launches.