Issue 1:
Here's the error

Error: Plugin 0 specified in "/home/ubuntu/grok/source/node_modules/next/babel.js" provided an invalid property of "default" (While processing preset: "/home/ubuntu/grok/source/node_modules/next/babel.js")
at Plugin.init (/home/ubuntu/grok/source/node_modules/babel-register/node_modules/babel-core/lib/transformation/plugin.js:131:13)
at Function.normalisePlugin (/home/ubuntu/grok/source/node_modules/babel-register/node_modules/babel-core/lib/transformation/file/options/option-manager.js:152:12)
at /home/ubuntu/grok/source/node_modules/babel-register/node_modules/babel-core/lib/transformation/file/options/option-manager.js:184:30
at Array.map (<anonymous>)
at Function.normalisePlugins (/home/ubuntu/grok/source/node_modules/babel-register/node_modules/babel-core/lib/transformation/file/options/option-manager.js:158:20)
at OptionManager.mergeOptions (/home/ubuntu/grok/source/node_modules/babel-register/node_modules/babel-core/lib/transformation/file/options/option-manager.js:234:36)
at /home/ubuntu/grok/source/node_modules/babel-register/node_modules/babel-core/lib/transformation/file/options/option-manager.js:265:14
at /home/ubuntu/grok/source/node_modules/babel-register/node_modules/babel-core/lib/transformation/file/options/option-manager.js:323:22
at Array.map (<anonymous>)
at OptionManager.resolvePresets (/home/ubuntu/grok/source/node_modules/babel-register/node_modules/babel-core/lib/transformation/file/options/option-manager.js:275:20)

And here's the dependencies and babel config of my package.json

{
"dependencies": {
"@babel/core": "7.0.0-beta.44",
"@babel/plugin-proposal-decorators": "7.0.0-beta.44",
"@babel/polyfill": "7.0.0-beta.44",
"@babel/preset-env": "7.0.0-beta.44",
"@babel/preset-stage-0": "7.0.0-beta.44",
"@babel/register": "7.0.0-beta.44",
"auto-sni": "2.3.2",
"body-parser": "1.18.2",
"chalk": "2.3.0",
"compression": "1.7.2",
"cookie-parser": "1.4.3",
"cookies": "0.7.1",
"credential": "2.0.0",
"elasticlunr": "0.9.5",
"encode32": "1.1.0",
"expect": "22.0.3",
"express": "4.16.2",
"express-await": "0.0.4",
"express-brute": "1.0.1",
"express-force-ssl": "0.3.2",
"express-graceful-exit": "0.4.1",
"fingerprintjs2": "1.5.1",
"forcedomain": "0.8.1",
"glamor": "2.20.40",
"glamorous": "4.11.2",
"goby": "1.1.2",
"google-id-token-verifier": "0.2.3",
"helmet": "3.12.0",
"homoglyph": "1.1.2",
"immutable": "3.8.2",
"is-hotkey": "0.1.2",
"isomorphic-unfetch": "2.0.0",
"js-base64": "2.4.3",
"js-cookie": "2.2.0",
"json-stringify-safe": "5.0.1",
"json5": "1.0.1",
"jsonfile": "4.0.0",
"jwt-simple": "0.5.1",
"keymaster": "1.6.2",
"luxon": "1.1.0",
"material-ui": "0.20.0",
"mobx": "4.1.1",
"mobx-react": "5.0.0",
"next": "6.0.0",
"next-cookies": "1.0.2",
"node-ssh": "5.1.1",
"nodemailer": "4.6.3",
"nodemailer-mailgun-transport": "1.3.6",
"nprogress": "0.2.0",
"pg": "7.4.0",
"platform": "1.3.4",
"prop-types": "15.6.0",
"react": "16.3.1",
"react-anime": "2.0.1",
"react-dnd": "2.5.4",
"react-dnd-html5-backend": "2.2.4",
"react-dom": "16.3.1",
"react-html-email": "3.0.0",
"react-keydown": "1.7.0",
"react-modal": "3.1.10",
"react-ripples": "1.1.2",
"react-scroll": "1.7.5",
"react-select": "1.1.0",
"react-stickynode": "1.4.0",
"react-tap-event-plugin": "3.0.2",
"react-tooltip": "3.4.0",
"react-transition-group": "2.2.1",
"react-youtube": "7.5.0",
"redirect-https": "1.1.5",
"request-ip": "2.0.2",
"slate": "0.33.5",
"slate-auto-replace": "0.9.0",
"slate-html-serializer": "0.6.2",
"slate-react": "0.12.5",
"textversionjs": "1.0.2",
"universal-analytics": "0.4.16",
"url-parse": "1.2.0",
"uuid": "3.1.0",
"webpack-bundle-analyzer": "2.9.1",
"webpack-bundle-size-analyzer": "2.7.0",
"winston": "2.4.1",
"winston-loggly-bulk": "2.0.2"
},
"devDependencies": {
"@babel/core": "7.0.0-beta.44",
"@types/jest": "22.1.1",
"@types/node": "9.4.7",
"@types/react-dom": "16.0.4",
"@zeit/next-typescript": "0.0.10",
"babel-core": "^7.0.0-bridge.0",
"babel-plugin-module-resolver": "3.0.0",
"babel-plugin-transform-decorators-legacy": "1.3.4",
"concurrently": "3.5.1",
"cross-env": "5.1.3",
"jest": "22.4.3",
"nodemon": "1.14.7",
"typescript": "2.8.1"
},
"babel": {
"presets": [
"next/babel"
],
"plugins": [
"transform-decorators-legacy",
[
"module-resolver",
{
"root": [
"."
]
}
]
]
}
}

Issue 2:
I just upgraded to next@6.0.0, I use a custom server, when I try to run dev, I get an error.

npm run dev

> frontend-next@1.0.0 dev /Users/foo/gitlab/next-project/backend
> babel-node ./src/server.js

/Users/foo/gitlab/next-project/backend/node_modules/babel-core/lib/transformation/file/options/option-manager.js:328
throw e;
^

Error: Plugin 0 specified in "/Users/foo/gitlab/next-project/backend/node_modules/next/babel.js" provided an invalid property of "default" (While processing preset: "/Users/foo/gitlab/next-project/backend/node_modules/next/babel.js")
at Plugin.init (/Users/foo/gitlab/next-project/backend/node_modules/babel-core/lib/transformation/plugin.js:131:13)
at Function.normalisePlugin (/Users/foo/gitlab/next-project/backend/node_modules/babel-core/lib/transformation/file/options/option-manager.js:152:12)
at /Users/foo/gitlab/next-project/backend/node_modules/babel-core/lib/transformation/file/options/option-manager.js:184:30
at Array.map (<anonymous>)
at Function.normalisePlugins (/Users/foo/gitlab/next-project/backend/node_modules/babel-core/lib/transformation/file/options/option-manager.js:158:20)
at OptionManager.mergeOptions (/Users/foo/gitlab/next-project/backend/node_modules/babel-core/lib/transformation/file/options/option-manager.js:234:36)
at /Users/foo/gitlab/next-project/backend/node_modules/babel-core/lib/transformation/file/options/option-manager.js:265:14
at /Users/foo/gitlab/next-project/backend/node_modules/babel-core/lib/transformation/file/options/option-manager.js:323:22
at Array.map (<anonymous>)
at OptionManager.resolvePresets (/Users/foo/gitlab/next-project/backend/node_modules/babel-core/lib/transformation/file/options/option-manager.js:275:20)
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! frontend-next@1.0.0 dev: `babel-node ./src/server.js`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the frontend-next@1.0.0 dev script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in:
npm ERR! /Users/foo/.npm/_logs/2018-04-30T08_41_09_819Z-debug.log

UPDATE all this passed after upgrading all babel packages to v7

Now this is the new error.... See below for complete error message

ERROR Failed to compile with 1 errors 10:32:07

error in ./pages/_document.js

Module build failed: Error: [BABEL] /Users/foo/gitlab/zyombo/backend/pages/_document.js: .value is not a valid Plugin property