[Typo3] htmlarea Imageproperties alttext

[Andreas Förthner]

Hi list,

in RTE htmlarea I can insert an image, but if I try to change the 
properties (right click -> imageproperties) I cannot save the form. 
Actually nothing happens if I click on save. How can I enable this, or 
is there another solution to insert the alttext for the image in the RTE?

Thanks

Greets

Andreas