Hi Sybre Waaijer,
thanks for feedback.
The conflict appears in Column “SEO” where all postings are listed in the backend:
<th scope="col" id="tsf-seo-bar-wrap" class="manage-column column-tsf-seo-bar-wrap">SEO</th>
The column is in that table:
<table class="wp-list-table widefat fixed striped posts">
I use Firefox, version 49.0.2 and Windows 7 Pro 64bit
Thanks
Cheers