Error: no implicit conversion of nil into String

Hi! I'm using Sketch 42 on macOS 10.11.6 with plugins installed via Chest (plus, Formr from my own repo). When I try to update plugins with chest update, I get this output:

Error: 409: unexpected token at '],
    },
    "identifier" : "com.animaapp.stc-sketch-plugin",
    "description": "Auto Layout for Sketch",
    "authorEmail" : "support@animaapp.com",
    "name" : "Auto Layout by Anima",
    "homepage": "http://www.animaapp.com",
    "version": "0.2.3",
    "manifestURL": "",
    "downloadURL": "",
    "compatibleVersion": 41,
    "bundleVersion": 1
}
'
Updated Compo (1.3 > 1.3)
Error: 743: unexpected token at '{
  "commands" : [
    {
      "script" : "script.cocoascript",
      "handler" : "setEven",
      "shortcut" : "ctrl alt shift e",
      "name" : "1:1",
      "identifier" : "even"
    },
    {
      "script" : "script.cocoascript",
      "handler" : "setHalf",
      "shortcut" : "ctrl alt shift h",
      "name" : "2:1",
      "identifier" : "half"
    },
    {
      "script" : "script.cocoascript",
      "handler" : "setThreeQuarters",
      "shortcut" : "ctrl alt shift j",
      "name" : "4:3",
      "identifier" : "threequarters"
    },
    {
      "script" : "script.cocoascript",
      "handler" : "setWidescreen",
      "shortcut" : "ctrl alt shift k",
      "name" : "16:9",
      "identifier" : "widescreen"
    },
    {
      "script" : "script.cocoascript",
      "handler" : "setCustom",
      "shortcut" : "ctrl alt shift l",
      "name" : "Parse Layer Name",
      "identifier" : "setcustom"
    }
  ],
  "menu": {
    "isRoot": false,
    "items": [
      "even",
      "half",
      "threequarters",
      "widescreen",
      "setcustom"
    ],
  },
  "identifier" : "com.example.sketch.formr",
  "compatibleVersion": 42,
  "name": "Formr",
  "version": 2.1.3,
  "description": "Plugin for Sketch app, helping to maintain proportions of layers and artboards",
  "keywords": [
    "sketch-app, plugin, proportion, layer, artboard, sketchapp"
  ],
  "author": "Sasha Katin",
  "authorEmail": "aleksandr.katin@gmail.com",
  "license": "MIT",
  "homepage": "https://github.com/lessthanzero/Formr",
  "repository": "https://github.com/lessthanzero/Formr.git",
  "updateURL": "https://github.com/downloads/example/sketchplugins/sketchplugins.json"
}
'
Error: no implicit conversion of nil into String
Updated reaction (1.0.0 > 1.0.0)
Updated 📏 Sketch Constraints (1.0 > 1.0)
Error: 409: unexpected token at '{
            "name": "Init",
            "identifier": "commandInit",
            "handlers": {
                    "actions": {
                        "OpenDocument": "commandInit",
                    }
                },
            "script": "mark.sketchscript"
        }
    ],
    "menu" : {
        "isRoot" : false,
        "shortcut" : "",
        "items" : [
            "commandToolbar",
            "-",
            "commandOverlays",
            "commandSizes",
            "commandSpacings",
            "commandProperties",
            "commandNote",
            "-",
            "commandExportable",
            "commandColor",
            "commandExport",
            "-",
            "commandHidden",
            "commandLocked",
            "commandClear",
            "-",
            "commandSettings",
            "linkDonate",
            {
              "title": "Help",
              "items": [
                "linkHelp",
                "linkFeedback",
                "linkDonate"
              ]
            }
        ],
        "title" : "Sketch Measure"
    },
    "identifier": "com.utom.measure",
    "homepage": "http://utom.design/measure/",
    "version": "2.4.2",
    "description" : "Make it a fun to create spec for developers and teammates",
    "authorEmail" : "utombox@gmail.com",
    "name" : "Sketch Measure"
}
'
Updated Sparkliner (2.0 > 2.0)
Updated Zeplin (1.2.1 > 1.2.1)
Error: no implicit conversion of nil into String

Seems like some conflict in manifest.js files. So conflicting plugins don't get updates. How do I fix it? Thanks in advance!

Sketch-Chest / chest

Error: no implicit conversion of nil into String #11