Activity not open

[PartapSBimrah]

I got this bug

E/AndroidRuntime: FATAL EXCEPTION: main Process: com.royalbimrah.social, PID: 19135 java.lang.RuntimeException: Unable to start activity ComponentInfo{com.royalbimrah.social/com.royalbimrah.social.MainActivity}: java.lang.IllegalArgumentException: Invalid document reference. Document references must have an even number of segments, but users has 1 at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3126) at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3269) at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:78) at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:108) at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:68) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1960) at android.os.Handler.dispatchMessage(Handler.java:106) at android.os.Looper.loop(Looper.java:214) at android.app.ActivityThread.main(ActivityThread.java:7081) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:494) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:965) Caused by: java.lang.IllegalArgumentException: Invalid document reference. Document references must have an even number of segments, but users has 1 at com.google.firebase.firestore.DocumentReference.forPath(com.google.firebase:firebase-firestore@@21.4.0:80) at com.google.firebase.firestore.CollectionReference.document(com.google.firebase:firebase-firestore@@21.4.0:104) at com.royalbimrah.social.query.QueryUtils.fetchUserInfo(QueryUtils.java:78) at com.royalbimrah.social.MainActivity.onCreate(MainActivity.java:131) at android.app.Activity.performCreate(Activity.java:7340) at android.app.Activity.performCreate(Activity.java:7331) at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1275) at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3106) at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3269)  at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:78)  at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:108)  at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:68)  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1960)  at android.os.Handler.dispatchMessage(Handler.java:106)  at android.os.Looper.loop(Looper.java:214)  at android.app.ActivityThread.main(ActivityThread.java:7081)