android support 25,Failed to resolve: com.android.support:design:25.0.1

Libraries from same "group" or referencing each others, must use the same version (when possible). Support llibraries, in particular, must have the same version of your compiled one.

You have implementation 'com.android.support:appcompat-v7:28.0.0-beta01' that is targeting a 28 Beta version and compile 'com.android.support:design:25.0.1' targeting 25 version.

Also you are probably using compileSdkVersion 28.

Implement support:design library to refer to version 28.0.0-beta01 too and it will (probably) will be fixed.

in shorts, use this gradle snippet:

implementation fileTree(dir: 'libs', include: ['*.jar'])

implementation 'com.android.support:appcompat-v7:28.0.0-beta01'

implementation 'com.android.support.constraint:constraint- layout:1.1.2'

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'

//add library

implementation 'com.android.support:design:28.0.0-beta01'

implementation 'com.firebaseui:firebase-ui:0.6.2'

(use implementation instead of compile since it will be replaced soon)

Hope this helps. Let me know if this solved!

Edit from comment below

Why are you using old versions? is there a reason?

increase firebase version also, the last should be 4.1

implementation 'com.firebaseui:firebase-ui-database:4.1.0'