Synchronizing failed: MalformedJsonException

[do0f]

Before creating an issue, please check if you're using the most up-to-date version of the plugin! Reinstall it if necessary.

If you're using a non stable KOReader version (one of the nightly builds), you may want to use the nightly branch instead.

• KOReader version:
  KOReader 2025.10 "Ghost"

Describe the Issue
Synching offline notes leads to the following error: "Synchronizing failed: MalformedJsonException"

Full log from KOReader (I copied it with OCR so it can be a little messed up):

Synchronizing failed!
com.google.gson.stream.MalformedJsonException: Use
JsonReader.setLenient(true) to accept malformed JSON at line 1 column 14 path com.googie.gson.jsonSyntaxException:
com.googie.gson.stream.MalformedJsonException: Use
JsonReader.setLenient(true) to accept malformed JSON at line 1 column 14 path $
at com.google.gson.JsonParser.parseReader(JsonParser.java:66)
at com.google.gson.jsonParser.parseString(JsonParser.java:47)
at com.kamwithk.ankiconnectandroid.routing.AnkiAPIRouting.findRouteHandl
@Error(AnkiAPIRouting.java:106)
com.kamwithk.ankiconnectandroid.routing.APIHandier.chooseAPIAPIHandi
er.java:33)
at com.kamwithk.ankiconnectandroid.routing.RouteHandier.get(RouteHandier
java:73)
at
fi.iki.elonen.router.RouterNanoHTTPD$DefaultStreamHandier.post(RouterN
anoHTTPD.java:100)
at fi.iki.elonen.router.RouterNanoHTTPD$UriResource.process(RouterNanoHT
TPD.java:386)
at fi.iki.elonen.router.RouterNanoHTTPD$UriRouter.process(RouterNanoHTTP
D.java:596)
at fl.iki.elonen.router.RouterNanoHTTPD.serve(RouterNanoHTTPD.java:671)
f.iki.elonen.NanoHTTPD$HTTPSession.execute(NanoHTTPD.java:945)
at fi.iki.elonen.NanoHTTPD$ClientHandier.run(NanoHTTPD.java:192)
at java.lang.Thread.run(Thread.java:923)
Caused by: com.google.gson.stream.Malformed/sonException: Use
JsonReader.setLenient(true) to accept malformed JSON at line 1 column 14 path at
com.google.gson.stream.jsonReader.syntaxError(JsonReader.java:1597)
com.google.gson.stream.JsonReader.checkLenient/sonReader.java:1404)
at com.google.gson.stream.JsonReader.doPeeK/sonReaderjava:542)
at com.google.gson.stream.JsonReader.peek/sonReader.java:425)
at com.google.gson./sonParser.parseReader(JsonParser.java:61)
... 11 more

I extracted anki.koplugin_notes.json and JSON there seems valid:

{"identifier":"Expression","data":{"modelName":"Lapis","tags":["KOReader"],"options":{"duplicateScope":"deck","allowDuplicate":false},"fields":{"MiscInfo":"Agatha Christie - And Then There Were None (195/351)","Sentence":"She and Philip Lombard sat on the <b>windowsill</b> of the living-room.","Expression":"windowsill","MainDefinition":"<div class=\"definition\"><ol>\n<i>noun</i><br><ol><li>(architecture) The horizontal member protruding from the base of a window frame.</li></ol></ol></div>"},"deckName":"English"},"field_callbacks":{"picture":{"func":"set_image_data","args":{}},"audio":{"field_name":"ExpressionAudio","func":"set_forvo_audio","args":["windowsill","en"]},"fields":{"func":"set_translated_context","args":["She and Philip Lombard sat on the <b>windowsill</b> of the living-room.","en"]}}}

[do0f]

ok, looks like the issue is with the AnkiconnectAndroid (KamWithK/AnkiconnectAndroid#89)
for anyone facing the same problem, I was able to fix it with simple Lua patch by just ignoring the MalformedJsonException error

[squishygian]

Hi do0f, I’m having this exact issue right now and it’s very frustrating 😢 I’m not super well versed technologically so if you don’t mind me asking, which lua file did you patch and how exactly did you patch it? Thank you!

[do0f]

Hi, you need to change a few lines in ankiconnect.lua
Then just replace this file in /plugins directory and relaunch KOReader

diff --git a/ankiconnect.lua b/ankiconnect.lua
index 15e5ee2..9c3f36e 100644
--- a/ankiconnect.lua
+++ b/ankiconnect.lua
@@ -56,21 +56,29 @@ function AnkiConnect:is_running(url)
     if not self.wifi_connected then
         return false, "WiFi disconnected."
     end
-    local anki_connect_request = { action = "requestPermission", version = 6 }
+    local anki_connect_request = { action = "requestPermission", version = "6" }
     local result, error = self:POST { payload = anki_connect_request, url = url }
     if error or result.permission == "denied" then
+        if error then
+            if error:find("MalformedJsonException", 1, true) then
+                result = { permission = "granted", requireApikey = false }
+                logger.warn("AnkiConnect is launched, but can't process the request, pretend everything is ok:", result)
+                return result
+            end
+            logger.warn("AnkiConnect post result:", error)
+        end
         return false, error or "Permission denied."
     end
     return result
 end
 
 function AnkiConnect:get_decknames(url, api_key)
-    local anki_connect_request = { action = "deckNames", version = 6, key = api_key }
+    local anki_connect_request = { action = "deckNames", version = "6", key = api_key }
     return self:POST { payload = anki_connect_request, url = url }
 end
 
 function AnkiConnect:request_add_note(note)
-    local anki_connect_request = { action = "addNote", params = { note = note }, version = 6, key = conf.api_key:get_value() }
+    local anki_connect_request = { action = "addNote", params = { note = note }, version = "6", key = conf.api_key:get_value() }
     return self:POST { payload = anki_connect_request, url = conf.url:get_value() }
 end
 
@@ -262,7 +270,7 @@ function AnkiConnect:delete_latest_note()
         local api_key = conf.api_key:get_value()
         -- don't use rapidjson, the anki note ids are 64bit integers, they are turned into different numbers by the json library
         -- presumably because 32 vs 64 bit architecture
-        local delete_request = ([[{"action": "deleteNotes", "version": 6, "params": {"notes": [%d]}, "key": %s }]]):format(latest.id, api_key and ([["%s"]]):format(api_key) or "null")
+        local delete_request = ([[{"action": "deleteNotes", "version": "6", "params": {"notes": [%d]}, "key": %s }]]):format(latest.id, api_key and ([["%s"]]):format(api_key) or "null")
         local _, err = self:POST { payload = delete_request, url = conf.url:get_value() }
         if err then
             return self:show_popup(("Couldn't delete note: %s!"):format(err), 3, true)

[squishygian]

Thank you for replying! But I think I have a different file than you because I don’t see the “anki_connect_request…=
request_permission” section, I tried changing the other things you included but it still doesn’t work

edit: nvm I found it! It was just formatted slightly differently, I will try now!

2nd edit: IT WORKS!!!!! THANK YOU!!!!!!!

[nairyosangha]

I think this issue should remain open until it's fixed on the AnkiConnectAndroid side. As @mallomar pointed out there, we're actually following the spec so I'd rather not update it here, but other people might run into it until it's fixed

[mallomar]

Just an FYI @do0f @squishygian @nairyosangha, I put in a PR for AnkiConnect Android to fix this issue in early October. If anyone wants to lovingly ask the developer there to implement the PR, here it is.