Bug "Failed To Resolve Packages: The File packages\manifest.json is not valid jason"

When I attempt to open my project with unity editor version 2021.3.4f1, I receive the following error message;

Where to go from here? Using reimport all from the asset menu does not work.

 

did you manually edit the manifest.json?
maybe attach it here so someone can point out the issue

 

I do not believe I manually edited this file, but here is the file text (I was not allowed JSON as an attachment).:

Code (CSharp):

1. {
2.   "dependencies": {
3.     "com.unity.2d.sprite": "1.0.0",
4.     "com.unity.2d.tilemap": "1.0.0",
5.     "com.unity.ads": "3.7.5",
6.     "com.unity.analytics": "3.6.11",
7.     "com.unity.collab-proxy": "1.15.15",
8.     "com.unity.collab-proxy": "1.9.0",
9.     "com.unity.collab-proxy": "1.14.15",
10.     "com.unity.ext.nunit": "1.0.6",
11.     "com.unity.ide.rider": "2.0.7",
12.     "com.unity.ide.visualstudio": "2.0.11",
13.     "com.unity.ide.vscode": "1.2.3",
14.     "com.unity.purchasing": "3.2.2",
15.     "com.unity.test-framework": "1.1.29",
16.     "com.unity.textmeshpro": "3.0.6",
17.     "com.unity.timeline": "1.4.8",
18.     "com.unity.ugui": "1.0.0",
19.     "com.unity.modules.ai": "1.0.0",
20.     "com.unity.modules.androidjni": "1.0.0",
21.     "com.unity.modules.animation": "1.0.0",
22.     "com.unity.modules.assetbundle": "1.0.0",
23.     "com.unity.modules.audio": "1.0.0",
24.     "com.unity.modules.cloth": "1.0.0",
25.     "com.unity.modules.director": "1.0.0",
26.     "com.unity.modules.imageconversion": "1.0.0",
27.     "com.unity.modules.imgui": "1.0.0",
28.     "com.unity.modules.jsonserialize": "1.0.0",
29.     "com.unity.modules.particlesystem": "1.0.0",
30.     "com.unity.modules.physics": "1.0.0",
31.     "com.unity.modules.physics2d": "1.0.0",
32.     "com.unity.modules.screencapture": "1.0.0",
33.     "com.unity.modules.terrain": "1.0.0",
34.     "com.unity.modules.terrainphysics": "1.0.0",
35.     "com.unity.modules.tilemap": "1.0.0",
36.     "com.unity.modules.ui": "1.0.0",
37.     "com.unity.modules.uielements": "1.0.0",
38.     "com.unity.modules.umbra": "1.0.0",
39.     "com.unity.modules.unityanalytics": "1.0.0",
40.     "com.unity.modules.unitywebrequest": "1.0.0",
41.     "com.unity.modules.unitywebrequestassetbundle": "1.0.0",
42.     "com.unity.modules.unitywebrequestaudio": "1.0.0",
43.     "com.unity.modules.unitywebrequesttexture": "1.0.0",
44.     "com.unity.modules.unitywebrequestwww": "1.0.0",
45.     "com.unity.modules.vehicles": "1.0.0",
46.     "com.unity.modules.video": "1.0.0",
47.     "com.unity.modules.vr": "1.0.0",
48.     "com.unity.modules.wind": "1.0.0",
49.     "com.unity.modules.xr": "1.0.0"
50.   }
51. }
52.  

 

Code (CSharp):

1.     "com.unity.collab-proxy": "1.15.15",
2.     "com.unity.collab-proxy": "1.9.0",
3.     "com.unity.collab-proxy": "1.14.15",

this package is listed three times for some reason
try removing the latter two lines and then reopen the project

 

I receive the same error message