Why I am getting this "Could not find com.google.firebase:firebase-core:16.1.0." error all the time?

Question

I am really fed up of these stupid android studio errors, the thing is I have included the implementation com.google.firebase:firebase-core:16.1.0 dependency in my build.gradle file but still am getting the error that says :::

Could not find com.google.firebase:firebase-core:16.1.0.

Also if I try to change it from 16.1.0 to 16.0.1 still error continues. How to fix this issue I have built almost 80% of my app and now when I just created new activity it is showing this error, I also deleted the activity but still issue continues. What is the fix for this? Thanks in advance!!

classpath 'com.google.gms:google-services:4.0.1'

And here is my Gradle file:

dependencies {
implementation fileTree(dir: 'libs', include: ['*.jar'])
implementation 'com.android.support:appcompat-v7:28.0.0'
implementation 'com.android.support.constraint:constraint-layout:1.1.3'
testImplementation 'junit:junit:4.12'
androidTestImplementation 'com.android.support.test:runner:1.0.2'
androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
implementation 'com.github.ittianyu:BottomNavigationViewEx:2.0.2'
implementation 'me.anwarshahriar:calligrapher:1.0'
implementation 'com.firebaseui:firebase-ui-database:4.3.1'
implementation 'com.google.firebase:firebase-database:16.0.1'
implementation 'com.google.firebase:firebase-auth:16.1.0'
implementation 'com.google.firebase:firebase-core:16.1.0'
implementation 'com.squareup.picasso:picasso:2.5.2'

}

Answer 1

Could not find com.google.firebase:firebase-core:16.1.0"

It happens because firebase-core:16.1.0 doesn't exist (today).
You can check the latest version here. Currently it is 16.0.7

Firebase Core com.google.firebase:firebase-core:16.0.7

Change your dependency in:

implementation 'com.google.firebase:firebase-core:16.0.7'