diff --git a/src/all/komga/build.gradle b/src/all/komga/build.gradle
index 38b8ca177..1cc7000b6 100644
--- a/src/all/komga/build.gradle
+++ b/src/all/komga/build.gradle
@@ -6,7 +6,7 @@ ext {
     extName = 'Komga'
     pkgNameSuffix = 'all.komga'
     extClass = '.KomgaFactory'
-    extVersionCode = 31
+    extVersionCode = 32
 }
 
 dependencies {
diff --git a/src/all/komga/src/eu/kanade/tachiyomi/extension/all/komga/Komga.kt b/src/all/komga/src/eu/kanade/tachiyomi/extension/all/komga/Komga.kt
index 682f8f6ac..d4df72492 100644
--- a/src/all/komga/src/eu/kanade/tachiyomi/extension/all/komga/Komga.kt
+++ b/src/all/komga/src/eu/kanade/tachiyomi/extension/all/komga/Komga.kt
@@ -32,12 +32,14 @@ import okhttp3.HttpUrl.Companion.toHttpUrlOrNull
 import okhttp3.OkHttpClient
 import okhttp3.Request
 import okhttp3.Response
+import okhttp3.ResponseBody
 import rx.Single
 import rx.android.schedulers.AndroidSchedulers
 import rx.schedulers.Schedulers
 import uy.kohesive.injekt.Injekt
 import uy.kohesive.injekt.api.get
 import uy.kohesive.injekt.injectLazy
+import java.security.MessageDigest
 import java.text.SimpleDateFormat
 import java.util.Date
 import java.util.Locale
@@ -176,20 +178,29 @@ open class Komga(suffix: String = "") : ConfigurableSource, HttpSource() {
     override fun mangaDetailsRequest(manga: SManga): Request =
         GET(manga.url, headers)
 
-    override fun mangaDetailsParse(response: Response): SManga =
-        if (response.fromReadList()) {
-            val readList = json.decodeFromString<ReadListDto>(response.body?.string()!!)
-            readList.toSManga()
-        } else {
-            val series = json.decodeFromString<SeriesDto>(response.body?.string()!!)
-            series.toSManga()
+    override fun mangaDetailsParse(response: Response): SManga {
+        val responseBody = response.body
+            ?: throw IllegalStateException("Response code ${response.code}")
+
+        return responseBody.use { body ->
+            if (response.fromReadList()) {
+                val readList = json.decodeFromString<ReadListDto>(body.string())
+                readList.toSManga()
+            } else {
+                val series = json.decodeFromString<SeriesDto>(body.string())
+                series.toSManga()
+            }
         }
+    }
 
     override fun chapterListRequest(manga: SManga): Request =
         GET("${manga.url}/books?unpaged=true&media_status=READY&deleted=false", headers)
 
     override fun chapterListParse(response: Response): List<SChapter> {
-        val page = json.decodeFromString<PageWrapperDto<BookDto>>(response.body?.string()!!).content
+        val responseBody = response.body
+            ?: throw IllegalStateException("Response code ${response.code}")
+
+        val page = responseBody.use { json.decodeFromString<PageWrapperDto<BookDto>>(it.string()).content }
 
         val r = page.mapIndexed { index, book ->
             SChapter.create().apply {
@@ -207,7 +218,10 @@ open class Komga(suffix: String = "") : ConfigurableSource, HttpSource() {
         GET("${chapter.url}/pages")
 
     override fun pageListParse(response: Response): List<Page> {
-        val pages = json.decodeFromString<List<PageDto>>(response.body?.string()!!)
+        val responseBody = response.body
+            ?: throw IllegalStateException("Response code ${response.code}")
+
+        val pages = responseBody.use { json.decodeFromString<List<PageDto>>(it.string()) }
         return pages.map {
             val url = "${response.request.url}/${it.number}" +
                 if (!supportedImageTypes.contains(it.mediaType)) {
@@ -223,13 +237,18 @@ open class Komga(suffix: String = "") : ConfigurableSource, HttpSource() {
     }
 
     private fun processSeriesPage(response: Response): MangasPage {
-        if (response.fromReadList()) {
-            with(json.decodeFromString<PageWrapperDto<ReadListDto>>(response.body?.string()!!)) {
-                return MangasPage(content.map { it.toSManga() }, !last)
-            }
-        } else {
-            with(json.decodeFromString<PageWrapperDto<SeriesDto>>(response.body?.string()!!)) {
-                return MangasPage(content.map { it.toSManga() }, !last)
+        val responseBody = response.body
+            ?: throw IllegalStateException("Response code ${response.code}")
+
+        return responseBody.use { body ->
+            if (response.fromReadList()) {
+                with(json.decodeFromString<PageWrapperDto<ReadListDto>>(body.string())) {
+                    MangasPage(content.map { it.toSManga() }, !last)
+                }
+            } else {
+                with(json.decodeFromString<PageWrapperDto<SeriesDto>>(body.string())) {
+                    MangasPage(content.map { it.toSManga() }, !last)
+                }
             }
         }
     }
@@ -350,10 +369,17 @@ open class Komga(suffix: String = "") : ConfigurableSource, HttpSource() {
     private var authors = emptyMap<String, List<AuthorDto>>() // roles to list of authors
 
     override val name = "Komga${if (suffix.isNotBlank()) " ($suffix)" else ""}"
-    override val lang = "en"
+    override val lang = "all"
     override val supportsLatest = true
     private val LOG_TAG = "extension.all.komga${if (suffix.isNotBlank()) ".$suffix" else ""}"
 
+    // keep the previous ID when lang was "en", so that preferences and manga bindings are not lost
+    override val id by lazy {
+        val key = "${name.toLowerCase()}/en/$versionId"
+        val bytes = MessageDigest.getInstance("MD5").digest(key.toByteArray())
+        (0..7).map { bytes[it].toLong() and 0xff shl 8 * (7 - it) }.reduce(Long::or) and Long.MAX_VALUE
+    }
+
     override val baseUrl by lazy { getPrefBaseUrl() }
     private val username by lazy { getPrefUsername() }
     private val password by lazy { getPrefPassword() }
@@ -428,8 +454,15 @@ open class Komga(suffix: String = "") : ConfigurableSource, HttpSource() {
                 .subscribe(
                     { response ->
                         libraries = try {
-                            json.decodeFromString(response.body?.string()!!)
+                            val responseBody = response.body
+                            if (responseBody != null) {
+                                responseBody.use { json.decodeFromString(it.string()) }
+                            } else {
+                                Log.e(LOG_TAG, "error while decoding JSON for libraries filter: response body is null. Response code: ${response.code}")
+                                emptyList()
+                            }
                         } catch (e: Exception) {
+                            Log.e(LOG_TAG, "error while decoding JSON for libraries filter", e)
                             emptyList()
                         }
                     },
@@ -446,8 +479,15 @@ open class Komga(suffix: String = "") : ConfigurableSource, HttpSource() {
                 .subscribe(
                     { response ->
                         collections = try {
-                            json.decodeFromString<PageWrapperDto<CollectionDto>>(response.body?.string()!!).content
+                            val responseBody = response.body
+                            if (responseBody != null) {
+                                responseBody.use { json.decodeFromString<PageWrapperDto<CollectionDto>>(it.string()).content }
+                            } else {
+                                Log.e(LOG_TAG, "error while decoding JSON for collections filter: response body is null. Response code: ${response.code}")
+                                emptyList()
+                            }
                         } catch (e: Exception) {
+                            Log.e(LOG_TAG, "error while decoding JSON for collections filter", e)
                             emptyList()
                         }
                     },
@@ -464,8 +504,15 @@ open class Komga(suffix: String = "") : ConfigurableSource, HttpSource() {
                 .subscribe(
                     { response ->
                         genres = try {
-                            json.decodeFromString(response.body?.string()!!)
+                            val responseBody = response.body
+                            if (responseBody != null) {
+                                responseBody.use { json.decodeFromString(it.string()) }
+                            } else {
+                                Log.e(LOG_TAG, "error while decoding JSON for genres filter: response body is null. Response code: ${response.code}")
+                                emptySet()
+                            }
                         } catch (e: Exception) {
+                            Log.e(LOG_TAG, "error while decoding JSON for genres filter", e)
                             emptySet()
                         }
                     },
@@ -482,8 +529,15 @@ open class Komga(suffix: String = "") : ConfigurableSource, HttpSource() {
                 .subscribe(
                     { response ->
                         tags = try {
-                            json.decodeFromString(response.body?.string()!!)
+                            val responseBody = response.body
+                            if (responseBody != null) {
+                                responseBody.use { json.decodeFromString(it.string()) }
+                            } else {
+                                Log.e(LOG_TAG, "error while decoding JSON for tags filter: response body is null. Response code: ${response.code}")
+                                emptySet()
+                            }
                         } catch (e: Exception) {
+                            Log.e(LOG_TAG, "error while decoding JSON for tags filter", e)
                             emptySet()
                         }
                     },
@@ -500,8 +554,15 @@ open class Komga(suffix: String = "") : ConfigurableSource, HttpSource() {
                 .subscribe(
                     { response ->
                         publishers = try {
-                            json.decodeFromString(response.body?.string()!!)
+                            val responseBody = response.body
+                            if (responseBody != null) {
+                                responseBody.use { json.decodeFromString(it.string()) }
+                            } else {
+                                Log.e(LOG_TAG, "error while decoding JSON for publishers filter: response body is null. Response code: ${response.code}")
+                                emptySet()
+                            }
                         } catch (e: Exception) {
+                            Log.e(LOG_TAG, "error while decoding JSON for publishers filter", e)
                             emptySet()
                         }
                     },
@@ -518,9 +579,16 @@ open class Komga(suffix: String = "") : ConfigurableSource, HttpSource() {
                 .subscribe(
                     { response ->
                         authors = try {
-                            val list: List<AuthorDto> = json.decodeFromString(response.body?.string()!!)
-                            list.groupBy { it.role }
+                            val responseBody = response.body
+                            if (responseBody != null) {
+                                val list = responseBody.use<ResponseBody, List<AuthorDto>> { json.decodeFromString(it.string()) }
+                                list.groupBy { it.role }
+                            } else {
+                                Log.e(LOG_TAG, "error while decoding JSON for authors filter: response body is null. Response code: ${response.code}")
+                                emptyMap()
+                            }
                         } catch (e: Exception) {
+                            Log.e(LOG_TAG, "error while decoding JSON for authors filter", e)
                             emptyMap()
                         }
                     },