diff --git a/app/src/main/assets/pl-changelog.html b/app/src/main/assets/pl-changelog.html
index dbb51c25..a8944f04 100644
--- a/app/src/main/assets/pl-changelog.html
+++ b/app/src/main/assets/pl-changelog.html
@@ -1,7 +1,8 @@
-<h3>Wersja 4.3, 2020-08-26</h3>
+<h3>Wersja 4.3.1, 2020-08-27</h3>
 <ul>
     <li>Dodana opcja automatycznej archiwizacji profilu na nowy rok szkolny.</li>
     <li>Poprawione problemy z synchronizacją oraz mieszaniem się danych.</li>
+    <li>Przywrócona synchronizacja w wakacje.</li>
 </ul>
 <br>
 <br>
diff --git a/app/src/main/cpp/szkolny-signing.cpp b/app/src/main/cpp/szkolny-signing.cpp
index e2a5a9c1..8e1f92dd 100644
--- a/app/src/main/cpp/szkolny-signing.cpp
+++ b/app/src/main/cpp/szkolny-signing.cpp
@@ -9,7 +9,7 @@
 
 /*secret password - removed for source code publication*/
 static toys AES_IV[16] = {
-	0x20, 0x98, 0x82, 0x66, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff  };
+	0x24, 0x85, 0x31, 0x5b, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff  };
 
 unsigned char *agony(unsigned int laugh, unsigned char *box, unsigned char *heat);
 
diff --git a/app/src/main/java/pl/szczodrzynski/edziennik/data/api/Constants.kt b/app/src/main/java/pl/szczodrzynski/edziennik/data/api/Constants.kt
index 60d0da59..af006d5a 100644
--- a/app/src/main/java/pl/szczodrzynski/edziennik/data/api/Constants.kt
+++ b/app/src/main/java/pl/szczodrzynski/edziennik/data/api/Constants.kt
@@ -24,14 +24,14 @@ const val FAKE_LIBRUS_ACCOUNTS = "/synergia_accounts.php"
 
 val LIBRUS_USER_AGENT = "${SYSTEM_USER_AGENT}LibrusMobileApp"
 const val SYNERGIA_USER_AGENT = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) Gecko/20100101 Firefox/62.0"
-const val LIBRUS_CLIENT_ID = "6XPsKf10LPz1nxgHQLcvZ1KM48DYzlBAhxipaXY8"
-const val LIBRUS_REDIRECT_URL = "http://localhost/bar"
+const val LIBRUS_CLIENT_ID = "0RbsDOkV9tyKEQYzlLv5hs3DM1ukrynFI4p6C1Yc"
+const val LIBRUS_REDIRECT_URL = "app://librus"
 const val LIBRUS_AUTHORIZE_URL = "https://portal.librus.pl/oauth2/authorize?client_id=$LIBRUS_CLIENT_ID&redirect_uri=$LIBRUS_REDIRECT_URL&response_type=code"
 const val LIBRUS_LOGIN_URL = "https://portal.librus.pl/rodzina/login/action"
 const val LIBRUS_TOKEN_URL = "https://portal.librus.pl/oauth2/access_token"
 
-const val LIBRUS_ACCOUNT_URL = "/v2/SynergiaAccounts/fresh/" // + login
-const val LIBRUS_ACCOUNTS_URL = "/v2/SynergiaAccounts"
+const val LIBRUS_ACCOUNT_URL = "/v3/SynergiaAccounts/fresh/" // + login
+const val LIBRUS_ACCOUNTS_URL = "/v3/SynergiaAccounts"
 
 /** https://api.librus.pl/2.0 */
 const val LIBRUS_API_URL = "https://api.librus.pl/2.0"
diff --git a/app/src/main/java/pl/szczodrzynski/edziennik/data/api/edziennik/librus/login/LibrusLoginPortal.kt b/app/src/main/java/pl/szczodrzynski/edziennik/data/api/edziennik/librus/login/LibrusLoginPortal.kt
index 5198d155..f164e3ed 100644
--- a/app/src/main/java/pl/szczodrzynski/edziennik/data/api/edziennik/librus/login/LibrusLoginPortal.kt
+++ b/app/src/main/java/pl/szczodrzynski/edziennik/data/api/edziennik/librus/login/LibrusLoginPortal.kt
@@ -66,7 +66,7 @@ class LibrusLoginPortal(val data: DataLibrus, val onSuccess: () -> Unit) {
                     override fun onSuccess(text: String, response: Response) {
                         val location = response.headers().get("Location")
                         if (location != null) {
-                            val authMatcher = Pattern.compile("http://localhost/bar\\?code=([A-z0-9]+?)$", Pattern.DOTALL or Pattern.MULTILINE).matcher(location)
+                            val authMatcher = Pattern.compile("$LIBRUS_REDIRECT_URL\\?code=([A-z0-9]+?)$", Pattern.DOTALL or Pattern.MULTILINE).matcher(location)
                             when {
                                 authMatcher.find() -> {
                                     accessToken(authMatcher.group(1), null)
@@ -127,7 +127,7 @@ class LibrusLoginPortal(val data: DataLibrus, val onSuccess: () -> Unit) {
                 .callback(object : JsonCallbackHandler() {
                     override fun onSuccess(json: JsonObject?, response: Response) {
                         val location = response.headers()?.get("Location")
-                        if (location == "http://localhost/bar?command=close") {
+                        if (location == "$LIBRUS_REDIRECT_URL?command=close") {
                             data.error(ApiError(TAG, ERROR_LIBRUS_PORTAL_MAINTENANCE)
                                     .withApiResponse(json)
                                     .withResponse(response))
diff --git a/app/src/main/java/pl/szczodrzynski/edziennik/data/api/szkolny/interceptor/Signing.kt b/app/src/main/java/pl/szczodrzynski/edziennik/data/api/szkolny/interceptor/Signing.kt
index 087b8ef8..877bc0c9 100644
--- a/app/src/main/java/pl/szczodrzynski/edziennik/data/api/szkolny/interceptor/Signing.kt
+++ b/app/src/main/java/pl/szczodrzynski/edziennik/data/api/szkolny/interceptor/Signing.kt
@@ -46,6 +46,6 @@ object Signing {
 
     /*fun provideKey(param1: String, param2: Long): ByteArray {*/
     fun pleaseStopRightNow(param1: String, param2: Long): ByteArray {
-        return "$param1.MTIzNDU2Nzg5MDQC7Eh97U===.$param2".sha256()
+        return "$param1.MTIzNDU2Nzg5MDiVEOFGvG===.$param2".sha256()
     }
 }
diff --git a/app/src/main/java/pl/szczodrzynski/edziennik/data/db/entity/Profile.kt b/app/src/main/java/pl/szczodrzynski/edziennik/data/db/entity/Profile.kt
index eab4cb8b..0dbb8502 100644
--- a/app/src/main/java/pl/szczodrzynski/edziennik/data/db/entity/Profile.kt
+++ b/app/src/main/java/pl/szczodrzynski/edziennik/data/db/entity/Profile.kt
@@ -106,7 +106,7 @@ open class Profile(
         }
         return Date.getToday() >= dateYearEnd && Date.getToday().year > studentSchoolYearStart
     }
-    fun isBeforeYear() = Date.getToday() < dateSemester1Start
+    fun isBeforeYear() = false && Date.getToday() < dateSemester1Start
 
     var disabledNotifications: List<Long>? = null
 
diff --git a/build.gradle b/build.gradle
index da3c5573..fb7bfd13 100644
--- a/build.gradle
+++ b/build.gradle
@@ -5,8 +5,8 @@ buildscript {
         kotlin_version = '1.3.61'
 
         release = [
-                versionName: "4.3",
-                versionCode: 4030099
+                versionName: "4.3.1",
+                versionCode: 4030199
         ]
 
         setup = [