TYPO3: FCE tab shows more elements than actual template files

I have a wierd problem, which I'm unable to find the root of. I have my own extension installed adding custom fluid content elements (fce). In the FCE tab (when adding new content element to page) I have two more elements selectable than actual template files. But it's getting wierder both extra elements have no label and throw an error when I try to add them.

The structure is:

typo3conf
  └ ext
     └ my_fancy_extension
        ├ Configuration
        │  └ TypoScript
        │     └ setup.txt
        ├ Resources
        │  ├ Privat
        │  │  ├ Elements (... containing my template files)
        │  │  ├ Language (... containing only my locallang.xml file)
        │  │  └ Elements (... containing only one partial file)
        │  └ Public
        │     └ [...]
        └ [...]

I digged down page TSConfig in the BackEnd and found out that the one partial file and the one language file are "loaded" as template files.

But I set my_fancy_extension/Configuration/TypoScript/setup.txt:

plugin.tx_fed.fce.my_fancy_extension {
    templateRootPath = EXT:my_fancy_extension/Resources/Private/Elements/
    partialRootPath = EXT:my_fancy_extension/Resources/Private/Partials/
    layoutRootPath = EXT:fluidcontent/Resources/Private/Layouts/
}

... and made sure this file was included in fileadmin\default\ts\setup.ts. But it seems not the templates from ./Elements are loaded, but all files below the parent folder ../Privat.

I'm not this adept with TYPO3 and TypoScript yet, but I'm learning since a year now. This is the first time I ran in something like that and I don't know where to dig further...

Does anyone know an approach? If you need more information, please let me know.

Thanks in advance and best regards.

Solution

What a stupid situation... -.-

Another developer was interfering with templating. When he moved a partial file, he forgot to delete the old one on the server. Later when fluid was searching recursively through its templateRootPath it found this old partial file and treated it like a template file which led to this error.

I found out by synchronizing the whole projekt and checking for differences between my development build and the server.

Sorry for the enormous amount of hard facepalms this has caused and will cause for everybody reading this in the future...