I assume your native language is german. Then it is likely that you have set:
In consequence all(!) values for Zeit and Wert are loaded as string (text), not as numeric. So try to load the two fields with numeric values where ever possible. I defined new separators before loading from the csv-file:
SET ThousandSep=''; // leave it blank for the moment SET DecimalSep='.'; Load ...
The rest should be easy as most of your values in the two fields will be recognized as numeric (and therefor are visible in a linechart).