HTML Errors recognized by W3 Validator

Please leave some error examples. That's hard to guess what issues you mean.

Ok, if it helps... Here we go:

: Element div not allowed as child of element label in this context. (Suppressing further errors from this subtree.)

From line 99, column 2238; to line 99, column 2308

wmu-show'><div class='wmu-add-icon' title='Klick hier um eine Datei hochzuladen'>&nbsp;

Bad value for attribute src on element img: Must be non-empty.

From line 99, column 2582; to line 99, column 2618

w-remove'><img class='wmu-preview-img' src=''/>

An img element must have an alt attribute, except under certain conditions. For details, consult guidance on providing text alternatives for images.

From line 99, column 2582; to line 99, column 2618

w-remove'><img class='wmu-preview-img' src=''/>

Element div not allowed as child of element label in this context. (Suppressing further errors from this subtree.)

From line 99, column 2751; to line 99, column 2821

wmu-show'><div class='wmu-add-icon' title='Klick hier um eine Datei hochzuladen'>

Element div not allowed as child of element span in this context. (Suppressing further errors from this subtree.)

From line 99, column 5097; to line 99, column 5124

l__check"><div class="wpd-field-desc">

Element div not allowed as child of element span in this context. (Suppressing further errors from this subtree.)

From line 99, column 5239; to line 99, column 5266

pan></div><div class="wpd-field-desc">

and many others. Its not that hard to find: check your own Website with wpDiscuz Media Uploader made available with the W3 Validator tool.