Hi Sinkatze,
deleting the contents of your C:\Users\Sinkatze\Appdata\Local\DayZ folder - they should get downloaded again when you launch the game (and the error message should go away).
If that does not work, please verify your data - Steam Library > Rightclick on DayZ > Properties > Local Files > Verify integrity of game cache.
Please let me know if either helped.
Regards,
Andy

added dmp files because i get the same errors. can't commit the *.mdmp file because such "large file sizes are not supported".

ok...your advice lead to this:

deleted the whole contents of appdata DayZ folder. now whenever i try to join a server, the game starts all over again! again i see the BI logo then the early-access disclaimer and later get back into the menu.
Verifying my game did not help!

This all after i switched back from experimental to stable! game is now not longer playable for me!

reported: #22505

edit: switched back to experimental and everything seems back to normal :O

edit2: no here it goes again...my game stops and i get thrown out onto the desktop with this image (see attachment: be_cmd_update)...and the game starts all over again...

edit3: uploaded now a zip with all dumps

i have no idea why it worked this time around, but it did (at least for one particular server where i had this issue)!
procedure:

• delete all contents from /appdata/local/dayz/
• get rid of all startup-cmds
• start DayZ
• connect to server
• let the BE cmd-window pop up, game restarts
• connect to server
  • it works!

strange thing is also, there is still no *.ebo file but the game runs now nevertheless :O