Skype wird sofort gestartet und beendet

I had that problem - I found a post somewhere here about needing to delete the .Skype directory and now Skype 4.3 works. If you can find that post you will have your answer.

If you updated from Skype 4.2, this is because the database format has slightly changed. More precisely, the problem is that the format of how file transfer logs are stored differs slightly, and Skype 4.3 crashes right away because it cannot deal with the old format.

One possibility, as suggested in the other answer, is to completely remove your Skype directory (i.e., rm -r ~/.Skype). However, this also means that you will lose all your conversation history!

A much better solution is to fix the database yourself. Make sure Skype is not running, and proceed as follows:

1. Install sqlite3:

   sudo apt-get install sqlite3
   

2. Next, issue the following command:

   sqlite3 ~/.Skype/SKYPE_USERNAME/main.db
   

   ...where you have to replace SKYPE_USERNAME with your Skype username. This gets you inside Skype's SQLite database. There, issue the following command:

   UPDATE messages
     SET body_xml =(
       SELECT SUBSTR( body_xml, files_start, alt_end - files_start ) ||
              SUBSTR( body_xml, 0, files_start ) ||
              SUBSTR( body_xml, alt_end )
       FROM (
         SELECT msg.body_xml,
                instr( msg.body_xml, '<files' )  files_start,
                instr( msg.body_xml, 'alt="' ) + 5 alt_end
         FROM messages msg
         WHERE msg.id = messages.id
       )
     )
   WHERE type = 68
   AND body_xml NOT LIKE '<file%';
   

   And quit:

   .quit
   

And voilà! Next time you start Skype and log in, it should work fine, and you'll still have all your conversation history.

Source: http://community.skype.com/t5/Linux/Skype-4-3-crash-on-ubuntu-14-04/m-p/3349043/highlight/true#M9417