Describe the bug
When i add file to sharedplaylist, Syncplay will loop try to open the file, then disconnect from server and retry.
And MPC-HC can't open the file correctly.

To Reproduce
Steps to reproduce the behavior:

1. Open the Syncplay client and connect to the server correctly
2. Rightclick the empty sharedplaylist and choose video files or drag files into sharedplaylist
3. See error in the chatbox and then Syncplay will crashed

Expected behavior
MPC-HC open the file correctly and Syncplay run as normal, wait everyone ready

Screenshots
the loop message like this

Version and platform:

• OS: Windows 10 64-bit
• Syncplay version and build type: Syncplay 1.7.1 (Stable)
• Media player and version: MPC-HC 2.1.3.37 (64-bit)

Additional context
MPC-HC using madvr and lav splitter
Only if i set the empty file path will see this bug, like this screenshot

While i give it a filepath, the chatbox will still show warnings, but then i can use Syncplay correctly.

the chatbox warning message

<class 'twisted.python.failure.Failure'>
[Failure instance: Traceback: <class 'syncplay.players.mpc.MpcHcApi.PlayerNotReadyException'>:
twisted\python\log.pyc:80:callWithContext
twisted\python\context.pyc:117:callWithContext
twisted\python\context.pyc:82:callWithContext
syncplay\vendor\qt5reactor.pyc:160:_read
--- <exception caught here> ---
syncplay\vendor\qt5reactor.pyc:153:_read
twisted\internet\tcp.pyc:248:doRead
twisted\internet\tcp.pyc:253:_dataReceived
twisted\internet\endpoints.pyc:151:dataReceived
twisted\protocols\basic.pyc:549:dataReceived
syncplay\protocols.pyc:55:lineReceived
syncplay\protocols.pyc:26:handleMessages
syncplay\protocols.pyc:211:handleSet
syncplay\client.pyc:1823:changeToPlaylistIndex
syncplay\client.pyc:1798:loadDelayedPath
syncplay\client.pyc:608:openFile
syncplay\players\mpc.pyc:410:openFile
syncplay\utils.pyc:79:f_retry
syncplay\players\mpc.pyc:436:setPosition
]
[('', 'syncplayClient.py', 17, (), ()), ('main', 'syncplay\ep_client.pyc', 8, (), ()), ('run', 'syncplay\clientManager.pyc', 16, (), ()), ('start', 'syncplay\client.pyc', 894, (), ()), ('run', 'syncplay\vendor\qt5reactor.pyc', 303, (), ()), ('read', 'syncplay\vendor\qt5reactor.pyc', 166, (), ()), ('callWithLogger', 'twisted\python\log.pyc', 96, (), ()), ('callWithContext', 'twisted\python\log.pyc', 80, (), ()), ('callWithContext', 'twisted\python\context.pyc', 117, (), ()), ('callWithContext', 'twisted\python\context.pyc', 82, (), ()), ('_read', 'syncplay\vendor\qt5reactor.pyc', 160, (), ())]

.syncplay.log

MPV failed with returncode 0.
MPV start failed.
Traceback (most recent call last):
File "syncplay\vendor\python_mpv_jsonipc\python_mpv_jsonipc.pyc", line 462, in _start_mpv
File "syncplay\vendor\python_mpv_jsonipc\python_mpv_jsonipc.pyc", line 218, in init
File "syncplay\vendor\python_mpv_jsonipc\python_mpv_jsonipc.pyc", line 239, in _start_process
syncplay.vendor.python_mpv_jsonipc.python_mpv_jsonipc.MPVError: MPV not started.
(loop)
syncplay.vendor.python_mpv_jsonipc.python_mpv_jsonipc.MPVError: MPV not started.
:259: UserWarning: You are using cryptography on a 32-bit Python on a 64-bit Windows Operating System. Cryptography will be significantly faster if you switch to using a 64-bit Python.
:259: UserWarning: You are using cryptography on a 32-bit Python on a 64-bit Windows Operating System. Cryptography will be significantly faster if you switch to using a 64-bit Python.
WNDPROC return value cannot be converted to LRESULT
TypeError: WPARAM is simple, so must be an int object (got NoneType)
(loop)