Hi Morten Nielsen,
As you said, it might be the characters.
To resolve this error, determine the maximum string value allowed by your data source and then reduce the string length of the offending value accordingly.
The maximum string length is displayed in the error message directly after"varchar". Then, do one of the following tasks:
- If you are using a Microsoft Excel as data source, access and create a test row in the Excel file that contains the maximum length of the string values you expect to be entered in your data source. Excel uses the first few rows of the data to determine the maximum string length to enforce for string values. Save the file and connect to the data source from Tableau Desktop.
- If you are using Microsoft SQL as a data source, access and edit the table schema to make the string value large enough to hold all the field values.
This could help you as well:
- Empty the Windows TEMP folder (default location: C:\TEMP).
- Limit the size of the extract.
- Use Tableau Desktop on a 64-bit computer.
- Close other applications that you are not actively using.