Question: Every time I use a firebase command this error occurs:

```
...\WEBRTCTest\FirebaseRTC> firebase use --add

Error: Invalid project id: \.

```

```
\WEBRTCTest\FirebaseRTC> firebase use --clear

Error: Invalid project id: \.

```

The error occured after I accidently run the command:

```
firebase use \

```

Prior to that all was working fine.

I tried to reinstall firebase-tools using npm and also re-cloning the example project from github.
Also tried to logout using `firebase logout` but it gives me the same error:

```
\WEBRTCTest\FirebaseRTC> firebase use --clear

Error: Invalid project id: \.

```

I´m thankful for any idea as i´m stuck right now.

Answer: 
It seems Firebase CLI can get into a bad state if you accidentally `use` an invalid project name, then all commands will fail, even `firebase use --clear` (I'm using version 8.2.0)

This happens even if there is no `.firebaserc` file.

I got it to work by finding a valid project name in my Firebase Console on console.firebase.google.com and then run the firebase command `use --clear` but overriding the active project with the `--project` parameter indicating a valid project name, like this:

```
$ firebase use --clear --project="myvalidprojectname"
Cleared active project.

Run firebase use --add to define a new project alias.

```

Then subsequent commands will run smoothly.
i had to delete the `.firebaserc` file ( to the all commands work again