Since a couple of days I noticed that all Typo3 installations on 1und1 hosting packages did not succeed in processing images.
Checking the image processing in the Typo3 installation tool the tests did not succeed but returning the error message “There was no result from the ImageMagick operation”.
After investigating into the problem it turned out that 1und1 has updated their ImageMagick installation (now it is 6.6.0-4). The new version seems to require more resources which is prohibited by the 1und1 server configuration.
To fix the issue, it is required to limit the resources ImageMagick consumes to process the images.
This can be done by editing your typo3conf/localconf.php
Add the following line at the top of the file (or at least above the line “## INSTALL SCRIPT EDIT POINT TOKEN”)
// setting to enable image magick processing on 1und1 server
putenv('MAGICK_THREAD_LIMIT=1');
Then clean up your configuration cache and your installation should be up and running again.
The following thread led me to the solution:
http://www.typo3.net/forum/beitraege/108097/seite/5/