diff --git a/app/build.gradle b/app/build.gradle
index 03541645..d07b0d47 100755
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -62,8 +62,10 @@ android {
 		release {
 			minifyEnabled true
 			shrinkResources true
-			useProguard true
 			proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
+//			firebaseCrashlytics {
+//				mappingFileUploadEnabled true
+//			}
 		}
 		debug {
 			minifyEnabled false
diff --git a/app/proguard-rules.pro b/app/proguard-rules.pro
index 80ef6edc..f1fb4b7c 100755
--- a/app/proguard-rules.pro
+++ b/app/proguard-rules.pro
@@ -21,3 +21,6 @@
 #-renamesourcefileattribute SourceFile
 
 -keep class com.dimowner.audiorecorder.** { *; }
+
+-keepattributes SourceFile,LineNumberTable        # Keep file names and line numbers.
+-keep public class * extends java.lang.Exception  # Optional: Keep custom exceptions.
diff --git a/app/src/main/java/com/dimowner/audiorecorder/app/main/MainPresenter.java b/app/src/main/java/com/dimowner/audiorecorder/app/main/MainPresenter.java
index b1ac7db8..48da1d35 100644
--- a/app/src/main/java/com/dimowner/audiorecorder/app/main/MainPresenter.java
+++ b/app/src/main/java/com/dimowner/audiorecorder/app/main/MainPresenter.java
@@ -681,7 +681,7 @@ private void updateInformation(String format, int sampleRate, long size) {
 					default:
 						view.showInformation(settingsMapper.formatSize(size) + AppConstants.SEPARATOR
 								+ format + AppConstants.SEPARATOR
-								+ settingsMapper.convertSampleRateToString(sampleRate) + AppConstants.SEPARATOR
+								+ settingsMapper.convertSampleRateToString(sampleRate)
 						);
 				}
 			}
diff --git a/build.gradle b/build.gradle
index a2a9da61..5ca4f1cf 100755
--- a/build.gradle
+++ b/build.gradle
@@ -6,7 +6,7 @@ buildscript {
     }
 
     dependencies {
-        classpath 'com.android.tools.build:gradle:3.6.1'
+        classpath 'com.android.tools.build:gradle:4.0.0'
     }
 }
 
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index e8b56a2f..aa0cdb62 100755
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -1,6 +1,6 @@
-#Thu Aug 01 21:08:22 EEST 2019
+#Sat Jun 06 12:53:24 EEST 2020
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-5.6.4-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.1.1-all.zip