[Typo3-install] upgrade to 4.0 question

[edison]

Do you have problems by installing new extentions such as 
dropdown_sitemap?

I upgated my typo3.8.1 installation to 4.0 and I cannot work with this 
extentions, when I insert this plug-in in a page I get this error:

TYPO3 Fatal Error: Extension key "api_macmade" was NOT loaded! 
(t3lib_extMgm::extPath)

What is wrong with this extentions? because I did many tests with 3.8.1 
version of typo and it works perfect.

tks,

> Hi,
> 
> I have a (hopefully) simple question.
> 
> I have upgraded a site from 3.8.1 to 4.0 but the admin pages did not 
> change to the new "look". Functionality seem to be changed and the site 
> itself claims to be "4.0". Where did I made a mistake? Where should I 
> have a look, which configfile?
> 
> Thanks in advance,
> Akos
>