diff --git a/app/src/main/java/pl/szczodrzynski/edziennik/api/v2/ApiService.kt b/app/src/main/java/pl/szczodrzynski/edziennik/api/v2/ApiService.kt
index 280b5c64..f76a792b 100644
--- a/app/src/main/java/pl/szczodrzynski/edziennik/api/v2/ApiService.kt
+++ b/app/src/main/java/pl/szczodrzynski/edziennik/api/v2/ApiService.kt
@@ -84,6 +84,7 @@ class ApiService : Service() {
             apiError.profileId = taskProfileId
             EventBus.getDefault().post(SyncErrorEvent(apiError))
             errorList.add(apiError)
+            apiError.throwable?.printStackTrace()
             if (apiError.isCritical) {
                 notification.setCriticalError().post()
                 taskRunning = false
diff --git a/app/src/main/java/pl/szczodrzynski/edziennik/api/v2/librus/Librus.kt b/app/src/main/java/pl/szczodrzynski/edziennik/api/v2/librus/Librus.kt
index 66594fd7..d8b9e596 100644
--- a/app/src/main/java/pl/szczodrzynski/edziennik/api/v2/librus/Librus.kt
+++ b/app/src/main/java/pl/szczodrzynski/edziennik/api/v2/librus/Librus.kt
@@ -133,8 +133,7 @@ class Librus(val app: App, val profile: Profile?, val loginStore: LoginStore, va
     }
 
     override fun cancel() {
-        d(TAG, "Cancelled")
-        cancelled = true
+        data.cancel()
     }
 
     private fun wrapCallback(callback: EdziennikCallback): EdziennikCallback {
diff --git a/app/src/main/java/pl/szczodrzynski/edziennik/api/v2/librus/data/LibrusApi.kt b/app/src/main/java/pl/szczodrzynski/edziennik/api/v2/librus/data/LibrusApi.kt
index 497d4845..89ce94a7 100644
--- a/app/src/main/java/pl/szczodrzynski/edziennik/api/v2/librus/data/LibrusApi.kt
+++ b/app/src/main/java/pl/szczodrzynski/edziennik/api/v2/librus/data/LibrusApi.kt
@@ -77,7 +77,8 @@ open class LibrusApi(open val data: DataLibrus) {
                     data.error(ApiError(tag, EXCEPTION_LIBRUS_API_REQUEST)
                             .withResponse(response)
                             .withThrowable(e)
-                            .withApiResponse(json))
+                            .withApiResponse(json)
+                            .setCritical(false))
                 }
             }
 
diff --git a/app/src/main/java/pl/szczodrzynski/edziennik/api/v2/librus/data/LibrusData.kt b/app/src/main/java/pl/szczodrzynski/edziennik/api/v2/librus/data/LibrusData.kt
index fc91c2a2..84271b60 100644
--- a/app/src/main/java/pl/szczodrzynski/edziennik/api/v2/librus/data/LibrusData.kt
+++ b/app/src/main/java/pl/szczodrzynski/edziennik/api/v2/librus/data/LibrusData.kt
@@ -41,6 +41,10 @@ class LibrusData(val data: DataLibrus, val onSuccess: () -> Unit) {
 
     private fun useEndpoint(endpointId: Int, onSuccess: () -> Unit) {
         Utils.d(TAG, "Using endpoint $endpointId")
+        if (data.cancelled) {
+            Utils.d(TAG, "Skip endpoint $endpointId; cancelled")
+            return
+        }
         when (endpointId) {
             ENDPOINT_LIBRUS_API_ME -> {
                 data.startProgress(R.string.edziennik_progress_endpoint_student_info)
diff --git a/app/src/main/java/pl/szczodrzynski/edziennik/api/v2/librus/data/api/LibrusApiGrades.kt b/app/src/main/java/pl/szczodrzynski/edziennik/api/v2/librus/data/api/LibrusApiGrades.kt
index c6ae0c4a..1d3de92b 100644
--- a/app/src/main/java/pl/szczodrzynski/edziennik/api/v2/librus/data/api/LibrusApiGrades.kt
+++ b/app/src/main/java/pl/szczodrzynski/edziennik/api/v2/librus/data/api/LibrusApiGrades.kt
@@ -25,7 +25,7 @@ class LibrusApiGrades(override val data: DataLibrus,
             grades?.forEach { gradeEl ->
                 val grade = gradeEl.asJsonObject
 
-                val id = grade.get("id").asLong
+                val id = grade.get("Id").asLong
                 val categoryId = grade.get("Category").asJsonObject.get("Id").asLong
                 val name = grade.get("Grade").asString
                 val semester = grade.get("Semester").asInt
diff --git a/app/src/main/java/pl/szczodrzynski/edziennik/api/v2/models/ApiError.kt b/app/src/main/java/pl/szczodrzynski/edziennik/api/v2/models/ApiError.kt
index d7b21a90..825809f9 100644
--- a/app/src/main/java/pl/szczodrzynski/edziennik/api/v2/models/ApiError.kt
+++ b/app/src/main/java/pl/szczodrzynski/edziennik/api/v2/models/ApiError.kt
@@ -10,7 +10,7 @@ import im.wangchao.mhttp.Response
 
 class ApiError(val tag: String, val errorCode: Int) {
     var profileId: Int? = null
-    private var throwable: Throwable? = null
+    var throwable: Throwable? = null
     private var apiResponse: String? = null
     private var request: Request? = null
     private var response: Response? = null
diff --git a/app/src/main/java/pl/szczodrzynski/edziennik/api/v2/models/Data.kt b/app/src/main/java/pl/szczodrzynski/edziennik/api/v2/models/Data.kt
index 53b9cc9f..0e275be5 100644
--- a/app/src/main/java/pl/szczodrzynski/edziennik/api/v2/models/Data.kt
+++ b/app/src/main/java/pl/szczodrzynski/edziennik/api/v2/models/Data.kt
@@ -8,6 +8,7 @@ import com.google.gson.JsonObject
 import im.wangchao.mhttp.Response
 import pl.szczodrzynski.edziennik.App
 import pl.szczodrzynski.edziennik.api.v2.interfaces.EndpointCallback
+import pl.szczodrzynski.edziennik.api.v2.librus.Librus
 import pl.szczodrzynski.edziennik.data.api.AppError.*
 import pl.szczodrzynski.edziennik.data.db.modules.announcements.Announcement
 import pl.szczodrzynski.edziennik.data.db.modules.api.EndpointTimer
@@ -30,6 +31,8 @@ import pl.szczodrzynski.edziennik.data.db.modules.teachers.Teacher
 import pl.szczodrzynski.edziennik.data.db.modules.teams.Team
 import pl.szczodrzynski.edziennik.singleOrNull
 import pl.szczodrzynski.edziennik.toSparseArray
+import pl.szczodrzynski.edziennik.utils.Utils
+import pl.szczodrzynski.edziennik.utils.Utils.d
 import pl.szczodrzynski.edziennik.utils.models.Date
 import pl.szczodrzynski.edziennik.values
 import java.io.InterruptedIOException
@@ -41,6 +44,8 @@ open class Data(val app: App, val profile: Profile?, val loginStore: LoginStore)
 
     var fakeLogin = false
 
+    var cancelled = false
+
     val profileId
         get() = profile?.id ?: -1
 
@@ -255,6 +260,12 @@ open class Data(val app: App, val profile: Profile?, val loginStore: LoginStore)
         }
     }
 
+    fun cancel() {
+        d("Data", "Cancelled")
+        cancelled = true
+        saveData()
+    }
+
     fun error(tag: String, errorCode: Int, response: Response? = null, throwable: Throwable? = null, apiResponse: JsonObject? = null) {
         var code = when (throwable) {
             is UnknownHostException, is SSLException, is InterruptedIOException -> CODE_NO_INTERNET
@@ -264,7 +275,7 @@ open class Data(val app: App, val profile: Profile?, val loginStore: LoginStore)
                 else -> errorCode
             }
         }
-        callback.onError(ApiError(tag, code).apply { profileId = profile?.id ?: -1 }.withResponse(response).withThrowable(throwable).withApiResponse(apiResponse))
+        error(ApiError(tag, code).apply { profileId = profile?.id ?: -1 }.withResponse(response).withThrowable(throwable).withApiResponse(apiResponse))
     }
     fun error(tag: String, errorCode: Int, response: Response? = null, apiResponse: String? = null) {
         var code = when (null) {
@@ -275,9 +286,11 @@ open class Data(val app: App, val profile: Profile?, val loginStore: LoginStore)
                 else -> errorCode
             }
         }
-        callback.onError(ApiError(tag, code).apply { profileId = profile?.id ?: -1 }.withResponse(response).withApiResponse(apiResponse))
+        error(ApiError(tag, code).apply { profileId = profile?.id ?: -1 }.withResponse(response).withApiResponse(apiResponse))
     }
     fun error(apiError: ApiError) {
+        if (apiError.isCritical)
+            cancel()
         callback.onError(apiError)
     }
     fun progress(step: Int) {