[TYPO3-dev] SQL error in Typo3 back-end

[Pieter]

Hello all,

a user with limited rights gets a SQL error on my site when he creates a 
new tt_news record (no error while editing an existing record).  An 
administrator does not have the error.

The error message:
Warning: mysql_fetch_assoc(): supplied argument is not a valid MySQL 
result resource in <siteURL>/t3/typo3_src-3.8.1/t3lib/class.t3lib_db.php 
on line 741

I enabled the debug option in the Typo3 configuration but this is for FE 
only it seems (the name is [FE][debug]).  It does not give more info.

Is there an other way to find out the source of this message?

I'm using 3.8.1, tt_news 2.2.24 and news_author_rel 0.2.0
I uninstalled news_author_rel but that made no difference.

Kind regards,
Pieter