Sync errors when trying to sync using anki 2.0.52

[justpeanuts]

OS: Linux Mint 20.0
Python version: Python 3.8.10

Issue:
I am trying to use anki 2.0.52 (because of support for an addon, Advanced Previewer)
I followed the instructions in the readme and installed anki-sync-server.
i have anki 2.0.52 installed in the system.
I get the following error when trying to sync from inside anki 2.0.52 :-

Syncing failed:
AnkiWeb encountered an error. Please try again in a few minutes, and if the problem persists, please file a bug report.

The errors that are outputted by the running instance of anki-sync-server, when i try to sync from anki are as follows:-

[2022-09-17 13:15:43,252]:INFO:ankisyncd:ankisyncd [unknown version] (https://github.com/ankicommunity/anki-sync-server.git)
[2022-09-17 13:15:43,268]:INFO:ankisyncd:Loaded config from /home/arjun/LINUX_SOFTWARE/TRYING_OUT/anki-sync-server/src/ankisyncd.conf
[2022-09-17 13:15:43,269]:INFO:ankisyncd.users:Found auth_db_path in config, using SqliteUserManager for auth
[2022-09-17 13:15:43,269]:INFO:ankisyncd.sessions:Found session_db_path in config, using SqliteSessionManager for auth
[2022-09-17 13:15:43,270]:INFO:ankisyncd:Serving HTTP on 0.0.0.0 port 27701...
Traceback (most recent call last):
  File "/usr/lib/python3.8/wsgiref/handlers.py", line 137, in run
    self.result = application(self.environ, self.start_response)
  File "/home/arjun/LINUX_SOFTWARE/TRYING_OUT/anki-sync-server/src/ankisyncd/sync_app.py", line 517, in __call__
    w= self.__wrapped__(*args, **kwargs)
  File "/home/arjun/LINUX_SOFTWARE/TRYING_OUT/anki-sync-server/src/ankisyncd/sync_app.py", line 641, in __call__
    raise HTTPForbidden()
webob.exc.HTTPForbidden: Access was denied to this resource.
[2022-09-17 13:15:57,132]:INFO:ankisyncd.http:127.0.0.1 "POST /sync/meta HTTP/1.1" 500 59
Traceback (most recent call last):
  File "/usr/lib/python3.8/wsgiref/handlers.py", line 137, in run
    self.result = application(self.environ, self.start_response)
  File "/home/arjun/LINUX_SOFTWARE/TRYING_OUT/anki-sync-server/src/ankisyncd/sync_app.py", line 517, in __call__
    w= self.__wrapped__(*args, **kwargs)
  File "/home/arjun/LINUX_SOFTWARE/TRYING_OUT/anki-sync-server/src/ankisyncd/sync_app.py", line 641, in __call__
    raise HTTPForbidden()
webob.exc.HTTPForbidden: Access was denied to this resource.
[2022-09-17 13:16:10,182]:INFO:ankisyncd.http:127.0.0.1 "POST /sync/meta HTTP/1.1" 500 59
Traceback (most recent call last):
  File "/usr/lib/python3.8/wsgiref/handlers.py", line 137, in run
    self.result = application(self.environ, self.start_response)
  File "/home/arjun/LINUX_SOFTWARE/TRYING_OUT/anki-sync-server/src/ankisyncd/sync_app.py", line 517, in __call__
    w= self.__wrapped__(*args, **kwargs)
  File "/home/arjun/LINUX_SOFTWARE/TRYING_OUT/anki-sync-server/src/ankisyncd/sync_app.py", line 641, in __call__
    raise HTTPForbidden()
webob.exc.HTTPForbidden: Access was denied to this resource.
[2022-09-17 13:16:14,526]:INFO:ankisyncd.http:127.0.0.1 "POST /sync/meta HTTP/1.1" 500 59
Traceback (most recent call last):
  File "/usr/lib/python3.8/wsgiref/handlers.py", line 137, in run
    self.result = application(self.environ, self.start_response)
  File "/home/arjun/LINUX_SOFTWARE/TRYING_OUT/anki-sync-server/src/ankisyncd/sync_app.py", line 517, in __call__
    w= self.__wrapped__(*args, **kwargs)
  File "/home/arjun/LINUX_SOFTWARE/TRYING_OUT/anki-sync-server/src/ankisyncd/sync_app.py", line 641, in __call__
    raise HTTPForbidden()
webob.exc.HTTPForbidden: Access was denied to this resource.
[2022-09-17 13:16:54,025]:INFO:ankisyncd.http:127.0.0.1 "POST /sync/meta HTTP/1.1" 500 59
Traceback (most recent call last):
  File "/usr/lib/python3.8/wsgiref/handlers.py", line 137, in run
    self.result = application(self.environ, self.start_response)
  File "/home/arjun/LINUX_SOFTWARE/TRYING_OUT/anki-sync-server/src/ankisyncd/sync_app.py", line 517, in __call__
    w= self.__wrapped__(*args, **kwargs)
  File "/home/arjun/LINUX_SOFTWARE/TRYING_OUT/anki-sync-server/src/ankisyncd/sync_app.py", line 641, in __call__
    raise HTTPForbidden()
webob.exc.HTTPForbidden: Access was denied to this resource.
[2022-09-17 13:17:21,563]:INFO:ankisyncd.http:127.0.0.1 "POST /sync/meta HTTP/1.1" 500 59

Can someone please help by providing the exact instructions required to setup sync between anki 2.0.52 in linux and ankidroid ?

[dglava]

Sorry for not being able to help directly, but I had the same issue. It was an error in my setup with a reverse proxy and accessing the sync server remotely.

I don't know how you are connecting to your sync server, but my advice is to first try a simple, local connection and sort that one out. Make sure that no firewall is blocking connections and that you're pointing everything to the correct address in your clients/server.

[dobefore]

As far as I know,2.0 version may be not supported ,you could try https://github.com/dsnopek/anki-sync-server or https://github.com/tsudoko/anki-sync-server .Those are ones that have not been maintianed for long ,though I cannot guarantee that they would work.

Edit: Or just update from 2.0 to 2.1.