Please accept my apologies - I assumed that the database file would create on any path, including paths that are not yet in existance. When I tried to run client 2.0.8 with a command line database name I saw exactly the same messages as you, and the client immediately closed.
I created the path where I wanted the database file to be stored, then started the client. The new database was created in the now existing/valid assigned path, and the client ran correctly.
Just for clarity on some of the other settings for client 2.0.8 or 2.0.9.
The Client OSC Input port number must match the server OSC default port. The server config has a segment like:
<osc>
<default-port>6250</default-port>
<predefined-clients>
<predefined-client>
<address>127.0.0.1</address>
<port>5253</port>
</predefined-client>
</predefined-clients>
</osc>
This requires that the client OSC Input port number is set to 6250 (client default port). The predefined-client tags are optional and are not needed in many installations. When a client connects to a server, that server auto-enables an output OSC status stream directed to the IP address it received from the client to the UDP port defined in the tags.
If there are entries for a predefined client, the server also sends the OSC status stream to the defined addresses and ports. This supports users who write custom software that receives, parses and displays a sub-set of the server status. A useage example is a computer screen showing the name of the video file in each channel of the server, with the run time remaining on each file. Useful for the programme director or production assistant to know when the clip will finish and they are back with live studio/OB content.
The client OSC Output form entry must be addressed to the OSC listener on the target device. If the target device is a lighting desk controller at 192.168.74.23 listening on UDP port 9004 create an entry line in the OSC output with properties Name=Lighting , Address=192.168.74.23 , Port=9004
To fire the OSC message back at the client that issues the OSC message add an output line with a name such as self-trigger an address of 127.0.0.1 and a port of 6250.
To generate an OSC output in the client, add an OSC command from the library tools to the rundown. In the Inspector panel of the client, OSC output section, select your named device (e.g. self-trigger) from the Output drop down list. In the Path box enter the control command /control/GroupUID/play (borrowing from your earlier posting). Set the Message box to 1. Set the Type to Integer. The message and type are those required by the CasparCG Client OSC server.
Assuming an item in the rundown has the UID used in the OSC output message the item will fire when the F2 key is pressed with the OSC Output command selected. The client log will also note the OSC message and it’s actions.
If the above guideline do not get the operational functionality, there are other open-source tools that may help investigations such as Wireshark and BitFocus Companion.
Wireshark is very powerful, but can also be quite tricky to use if you are not familiar with network packet analysers. A complexity in the scenario discussed here is the status traffic and the OSC command can be interleaved. If the CasparCG server is not on local host then Wireshark captures on the local loopback interface only have the OSC command traffic.
BitFocus Companion was created to support the Elgato Stream Deck control lots of other kit, but can be used without the Stream Deck hardware as it has an emulator that runs in a modern web browser. You can set a button to generate the OSC command for the client. You can also send commands from the CasparCG client that press buttons in Companion. You see an indication in the button when a press happens. The press button button 7 on button page bank 1 the command is /press/bank/1/7 Message=1 Type=Integer. To release the button make the message value 0.
There are slight differences when using client 2.2.0 with a version 2.2.0 or newer server. The major changes are the OSC general monitor port used by the server status can be a different port to that used for OSC control of the client. As with client 2.0.9 there is also a UDP port por Web Socket messages. This make it relatively simple to create a web page on a tablet computer or similar that can trigger events in CasparCG client/server.