fixed in version 3.8.3
The tmui element won't be rendered if either there are no page buttons to show or page buttons have been disabled

Disable page buttons like this:
- Open Textmarker settings
- Choose tab "Misc"
- Uncheck the checkboxes for showing notes- and bookmark-button

Quick note on bug reports:
Please consider using the issue page on github instead of posting it in a review:
https://github.com/ufb/Textmarker/issues
Alternatively you can also write an e-mail