TYPO3 Core

Get error

Fatal error: Cannot instantiate non-existent class: t3lib_tceforms_fe in /typo3_src-3.7.0/t3lib/class.t3lib_div.php on line 3229

if I use admPanel in Frontend.

I use following in TSConfig (Group):
admPanel {
enable.edit = 1
enable.preview = 1
enbale.info = 1
module.edit.forceDisplayIcons = 1
module.edit.forceDisplayFieldIcons = 1
hide = 0
}

The fatal error comes up if I click at edit button under contents if the admPanel is closed in frontend.

If I open admPanel with click at the "plus" in Frontend I can use the edit button under contents.

I do not know if this comes up through other settings. Sometimes I feel me like a newbie but I work with Typo3 since nearly 10 weeks every day.
(issue imported from #M418)