Error: No Settings for the YAG Gallery were found on the selected page.

[papillon6]

Neither the module in backend, nor the frontend plugin is working in my case.

Although I added the static TS to my root page, the backend module of YAG shows an error/note:
"No Settings for the YAG Gallery were found on the selected page."

In frontend YAG tries to redirect to the current page adding the following GET-parameters ...
&tx_yag_pi1%5Baction%5D=settingsNotAvailable&tx_yag_pi1%5Bcontroller%5D=Backend
... which ends up in an error (ERR_TOO_MANY_REDIRECTS).

Further information:
TYPO3 7.6.23
YAG 4.2.1
PT_EXTBASE 2.3.0
PT_EXTLIST 2.4.0
PHP 7.1

Did I get something wrong or is it a bug?