[TYPO3-english] imagecycle error

[j.j]

Hi,

 I have installed this extension folowing the steps in tutorial. When i add the imagecycle element to content all is ok. But if i add a nivo-slider in my content i get errors in the backend:

t3lib_div::callUserFunction
|<strong>ERROR:</strong> No class named: tx_jftcaforms_tceFunc|

But nevertheless in front end the slider works. 
Any ideas hoe to solve the error?