react-native: react-native start giving Invalid regular expression invalid error

Try to downgrade your Node version. I’ve had the same issue after I upgraded from v12.8 => v12.11 After the downgrade it works again

Same problem here. The following fixed it:

choco uninstall nodejs
choco install nodejs-lts

I solved the issue refer this https://iamsapankumar.blogspot.com/2019/10/error-invalid-regular-expression.html?m=1&fbclid=IwAR24kM7FvVFPR9ZTdq6HAmFDvF-Th7MnV2IvS3Yo_F9m6snDFh_QNsr0vgs

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+1 on re-open, especially considering that the current LTS demonstrates this issue.

As @JasonHughes94 mentioned, node 12.9.1 seems to be most recent version which does not demonstrate this error. Direct downloads for 12.9.1 can be found here: https://nodejs.org/download/release/v12.9.1/

If you’re using chocolatey, you can explicitly install this version with the following:

choco install nodejs.install --version=12.9.1

Since this ticket seems to have the most history and context, I think we could reopen this one and close the following:

#26975 #26969 #26878 #26829 #26808

This should be resolved once https://github.com/facebook/metro/pull/464/files is landed and RN is updated to point to the latest.

The solution *** uninstall react native and move to an actual stable platform.

I downgrade Node version: choco install -y nodejs.install --version 10.16.3 --force

It’s still not fixed, why it’s closed?

Now instead of editing /node_modules you can add resolutions for metro-config in package.json as temporary workaround:

  "resolutions": {
    "metro-config": "0.57.0"
  },

This issue should be reopened - following the documentation correctly leads to this failure, which means this is an open problem

Downgrading is not an option if you really care for security. Believe or not, but sometimes newer versions of Node.js are fixing issues you should be concerned about.

Is anyone capable of providing insights on why there is an invalid regular expression or why at least some parser isn’t capable of adopting newer capabilities of distinguishing a forward slash inside a character class from a terminating forward slash? Please, provide details on why there are no upgrades for either involved dependency and why no one’s caring on behalf of this project. Eventually this is just proving how error-prone this npm-style of coding is: don’t use deps without checking whether they are implemented well enough for your tool. This ain’t Lego. According to this thread I sincerely doubt react-native was ever made for lasting long enough to become a favourable platform for software meant to have its own LTS versions …

Don’t downgrade. Otherwise consider downgrading to Windows XP or macOS 9 as well whenever your website does not look any good no more.

I downgrade Node version from 12.11.10 to the last stable version 10.16.3 LTS and it worked for me. Thanks @NyauIf

Take a look at this hope this works for you: https://stackoverflow.com/questions/55441230/unable-to-load-script-make-sure-you-are-either-running-a-metro-server-or-that-yo?newreg=834f28d14a0f4de0b6928f6c875beeaf

Go to this file: \node_modules\metro-config\src\defaults\blacklist.js and change this code:

var sharedBlacklist = [ /node_modules[/\]react[/\]dist[/\]./, /website/node_modules/./, /heapCapture/bundle.js/, /./tests/./ ]; and change to this:

var sharedBlacklist = [ /node_modules[/\]react[/\]dist[/\]./, /website/node_modules/./, /heapCapture/bundle.js/, /./tests/./ ];

This worked for me!!

yes i am also facing this issues. actually Node.js Recommended For Most Users is version 10.16.3 LTS. Using below choco command will install Latest version of 12.11.0.
choco install -y nodejs.install python2 jdk8

I downgrade Node version from 12.11.0 to 10.16.3 LTS and it worked for me.

Still hapenning with Node LTS 12.16.2, this should be fixed ASAP…

It’s still not fixed

12.8 works for the time being - separate issue #26808 opened about the same problem

choco uninstall nodejs
choco install nodejs --version 12.8

This issue has been fixed as of #468 in metro.

@ThaJay @zaidpathanGit @soletan Just update metro-react-native-babel-preset to latest 0.59.0 version and issue will be fixed. I’m on latest NodeJS 12.18.0 and react-native 0.62.2

@ahaq0 I am on Windows 10, what I did is the following:

1. react-native init appName --version="0.60.0"
2. open windows explorer and find this path in your app dir node_modules\metro-config\src\defaults there you will see blacklist.js, you can open it and edit the sharedBlacklist variable (array with regexs) by removing all / (forward slash symbol) which are not in the begging or in the end of a row (if there are 4-5 rows of regex, you should leave there only the first and last forward slashes)
3. open another terminal window and cd into the dir (appName) then react-native start (to start a metro server)
4. cd appName && react-native run-android in the first terminal window

changing blacklist.js file for ‘/’ slashes is temporary solution. after adding new dependency or ‘npm install’ or ‘yarn add’ commands you have to do it again.

I listen advives to downgrade nodeJS to 10.16.3 maybe 12.9.1 also works.( uninstall nodejs choco uninstall or windows program uninstall page, download versions from here whichever you want to try. ). I also init new project with optin –version=“0.60.0” maybe just that worked for me. for my old projects I dont know what to do.

I want permanent solution with a nodejs LTS release.

Simplest steps to fix this for me were:

1. Install yarn
2. Add resolution to package.json as per the comment from EugeneDraitsev above
3. Delete the node_modules directory and the package-lock.json file (if present)
4. run yarn install

React native setup is painful on win … i have stuck for 1 day for this problem.

Hey, as stated above with the release of Node 13 this had made the LTS now 12.13.0. You can revert back to 12.9.1 and this works as intended.

Is there a plan on this being fixed for the latest versions of Node?

Hello everyone. I had the same problem and this is what I did to solve it thanks to @NyauIf :

1. Uninstalled version v12.11: choco uninstall nodejs.install
2. Installed long-term support version v10.16.3: choco install nodejs-lts
3. Started metro server: cd project && react-native start

@profnandaa I found that changing the blacklist var worked: var sharedBlacklist = [ /node_modules[\/\\]react[\/\\]dist[\/\\].*/, /website\/node_modules\/.*/, /heapCapture\/bundle\.js/, /.*\/__tests__\/.*/ ];

I did this in the metro-config file

For me changing the code into node_modules\metro-config\src\defaults\blacklist.js as per following worked.

var sharedBlacklist = [
//node_modules[/\]react[/\]dist[/\]./,
//website/node_modules/./,
//heapCapture/bundle.js/,
//./tests/./
];

downgraded to 12.9.1, via windows uninstall and getting a previous version from here: https://nodejs.org/download/release/v12.9.1/ Terrible bug…

I’m getting the same problem here.

It appears in \node_modules\metro-config\src\defaults\blacklist.js, there is an invalid regular expression that needed changed. I changed the first expression under sharedBlacklist from:

var sharedBlacklist = [ /node_modules[/\]react[/\]dist[/\]./, /website/node_modules/./, /heapCapture/bundle.js/, /./tests/./ ];

to:

var sharedBlacklist = [ /node_modules[/\]react[/\]dist[/\]./, /website/node_modules/./, /heapCapture/bundle.js/, /./tests/./ ];

Having the issue with the new lts version so previous fixes will no longer work (as with the current latest 13.0.0) . As halkliff said, the lts version is now changed to 12.13.0. Can get it to work if you get 10.16.3 from https://nodejs.org/dist/

They should be working on compatibility with node 12 though, the 10.16.3 LTS node is going to be replaced by Node 12 in Oct. 22, 2019.

Spent a day looking at this, for me nothing mentioned above helped, I checked all packages for upgraded and it turned out to be an issue with ‘validator’ package, see this issue: https://github.com/validatorjs/validator.js/issues/1354

Edit: also I should say that in debug it was all fine, however as soon as I built in release mode and deployed on a device, I got this error.

None of the above solutions worked for me.

So I deleted node from control panel and then install downgraded version choco install nodejs --version 12.8

Now it is working.

Downgrading to nodejs 10.18.1 did it for me.

This sucks…!!!

+1 on re-open, especially considering that the current LTS demonstrates this issue.

As @JasonHughes94 mentioned, node 12.9.1 seems to be most recent version which does not demonstrate this error. Direct downloads for 12.9.1 can be found here: https://nodejs.org/download/release/v12.9.1/

If you’re using chocolatey, you can explicitly install this version with the following:

choco install nodejs.install --version=12.9.1

Since this ticket seems to have the most history and context, I think we could reopen this one and close the following:

#26975 #26969 #26878 #26829 #26808

This should be resolved once https://github.com/facebook/metro/pull/464/files is landed and RN is updated to point to the latest.

Only solution that worked for me was to downgrade node to the version of 12.9.1. Thanks! 😃

This is still very much an issue and should be reopened.

The mention of this fix should reach - http://facebook.github.io/react-native/docs/troubleshooting#content

You can manually uninstall it using the Control Panel in Windows and download whatever you want.

Thanks!. Done and working

You can manually uninstall it using the Control Panel in Windows and download whatever you want.

Hi, i have the same problem when i execute

react-native start

I tried to follow the steps but i have a problem when i uninstall with choco!

1º C:\WINDOWS\system32> node -v => v12.13.0 2º choco uninstall nodejs

Uninstalling the following packages:
nodejs
nodejs is not installed. Cannot uninstall a non-existent package.

How can is possible??? What can i do to uninstall and re-install?

Thanks!

@ahaq0 I am on Windows 10, what I did is the following:

1. react-native init appName --version="0.60.0"
2. open windows explorer and find this path in your app dir node_modules\metro-config\src\defaults there you will see blacklist.js, you can open it and edit the sharedBlacklist variable (array with regexs) by removing all / (forward slash symbol) which are not in the begging or in the end of a row (if there are 4-5 rows of regex, you should leave there only the first and last forward slashes)
3. open another terminal window and cd into the dir (appName) then react-native start (to start a metro server)
4. cd appName && react-native run-android in the first terminal window

@8bitpravibyte Try to remove node_modules and install it again or maybe try to use yarn instead of npm i

Actually, the version 12.10.0 is the latest that works. Still, the regex is incorrect nonetheless, and the newer versions of node won’t tolerate it anymore, so it needs to be fixed.

It won’t affect older versions, but surely will enable to be used in newer ones.

Just downgrade the Node version it will work fine. Best way to use https://github.com/nvm-sh/nvm it helps to change the node version as required,