my vue app breaks after i insall mdb vue i don know why, i see this error

warning in ./src/router/index.js

"export 'default' (imported as 'Router') was not found in 'vue-router'

warning in ./src/router/index.js

"export 'default' (imported as 'Router') was not found in 'vue-router'

warning in ./src/main.js

"export 'default' (imported as 'Vue') was not found in 'vue'

warning in ./src/main.js

"export 'default' (imported as 'Vue') was not found in 'vue'

warning in ./src/router/index.js

"export 'default' (imported as 'Vue') was not found in 'vue'

warning in ./src/store.js

"export 'default' (imported as 'Vue') was not found in 'vue'