Issue when syncing media

[gajewsk2]

In debug with media sync sometimes I get this:

192.168.0.24 - - [20/Aug/2017:16:01:39 -0500] "POST /sync/meta HTTP/1.1" 200 115 "-" "Python-httplib2/0.7.7 (gzip)"
Traceback (most recent call last):
  File "/usr/lib/python2.7/logging/__init__.py", line 851, in emit
    msg = self.format(record)
  File "/usr/lib/python2.7/logging/__init__.py", line 724, in format
    return fmt.format(record)
  File "/usr/lib/python2.7/logging/__init__.py", line 467, in format
    s = self._fmt % record.__dict__
MemoryError

I'm on ubuntu bash on windows. I managed to get the server running, but my deck has about 200k media cards. I originally got a memory error, but now the server in debug mode doesn't say anything and the anki client says the string buffer error below, under the condition i don't do a media sync.
I'm getting this ambiguous error and not able to figure out what the bad response actually is, since anki only throws this up:

Syncing failed:
Traceback (most recent call last):
  File "aqt\sync.py", line 324, in run
  File "aqt\sync.py", line 385, in _sync
  File "aqt\sync.py", line 416, in _syncMedia
  File "anki\sync.py", line 739, in sync
  File "anki\sync.py", line 873, in begin
  File "json\__init__.py", line 326, in loads
  File "json\decoder.py", line 366, in decode
TypeError: expected string or buffer

The reason for me doing a custom server is because I hope to get around the 250MB collection limit. Is it possible to only sync with the custom server your base and no media - since there is no restriction on collection media size?

I removed the line from mysyncserver.py to be, but get the same ambiguous error

import anki.sync
anki.sync.SYNC_BASE = 'http://127.0.0.1:27701/'

and removed anki.sync.SYNC_MEDIA_BASE = 'http://127.0.0.1:27701/msync/'

If I disable media sync, things work just fine.