diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index 6ab3d86..dd5de41 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -14,6 +14,7 @@
         android:roundIcon="@mipmap/ic_launcher_round"
         android:supportsRtl="true"
         android:theme="@style/Theme.Mimic3TTSEngineWrapper"
+        android:networkSecurityConfig="@xml/network_security_config"
         tools:targetApi="31">
         <activity
             android:name=".activities.LogActivity"
diff --git a/app/src/main/java/de/bentigorlich/mimic3ttsenginewrapper/tts/Mimic3TTSEngineWeb.java b/app/src/main/java/de/bentigorlich/mimic3ttsenginewrapper/tts/Mimic3TTSEngineWeb.java
index 8e6f65d..8d9e3de 100644
--- a/app/src/main/java/de/bentigorlich/mimic3ttsenginewrapper/tts/Mimic3TTSEngineWeb.java
+++ b/app/src/main/java/de/bentigorlich/mimic3ttsenginewrapper/tts/Mimic3TTSEngineWeb.java
@@ -473,6 +473,7 @@ private void synthesizeTextFromUrl(SharedPreferences preferences, int speechRate
             _Logger.severe("Malformed server url: " + ex.getMessage());
             ex.printStackTrace();
             synthesisCallback.error();
+            synthesisCallback.done();
         } catch (IOException ex) {
             _Logger.severe("Connection error: " + ex.getMessage());
             ex.printStackTrace();
@@ -499,6 +500,7 @@ private void synthesizeTextFromUrl(SharedPreferences preferences, int speechRate
                         in.close();
                     } catch (IOException ex2) {
                         synthesisCallback.error();
+                        synthesisCallback.done();
                         _Logger.severe("Cache error loading default_no_connection: " + ex2.getMessage());
                         ex.printStackTrace();
                         for (StackTraceElement el : ex.getStackTrace()) {
@@ -507,10 +509,12 @@ private void synthesizeTextFromUrl(SharedPreferences preferences, int speechRate
                     }
                 } else {
                     synthesisCallback.error();
+                    synthesisCallback.done();
                     _Logger.severe("default_no_connection was in cache, but file doesn't exist");
                 }
             } else {
                 synthesisCallback.error();
+                synthesisCallback.done();
                 _Logger.severe("default_no_connection was not in cache");
             }
         }
@@ -522,15 +526,19 @@ private void synthesizeTextFromCache(boolean specialKeySet, String specialKey, S
             try {
                 key = Mimic3TTSEngineWrapperApp.getSha256Hex(text);
             } catch (NoSuchAlgorithmException e) {
+                _Logger.severe("sha256 is not supported, should never happen...");
                 synthesisCallback.error();
+                synthesisCallback.done();
                 return;
             }
         } else {
             key = specialKey;
         }
         File cacheFile = new File(Mimic3TTSEngineWrapperApp.getStorageContext().getCacheDir(), key);
-        if(!cacheFile.exists())
+        if(!cacheFile.exists()) {
+            _Logger.severe("Should synthesize from cache, but there is no cache file...");
             throw new FileNotFoundException(key);
+        }
 
         _Logger.info("Synthesizing text with cache: " + text);
         try {
@@ -550,6 +558,7 @@ private void synthesizeTextFromCache(boolean specialKeySet, String specialKey, S
                 _Logger.warning("at " + el.toString());
             }
             synthesisCallback.error();
+            synthesisCallback.done();
         }
     }
 
diff --git a/app/src/main/res/xml/network_security_config.xml b/app/src/main/res/xml/network_security_config.xml
new file mode 100644
index 0000000..f18e1f0
--- /dev/null
+++ b/app/src/main/res/xml/network_security_config.xml
@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="utf-8"?>
+<network-security-config>
+    <base-config cleartextTrafficPermitted="true">
+        <trust-anchors>
+            <certificates src="system" />
+        </trust-anchors>
+    </base-config>
+</network-security-config>
\ No newline at end of file