294,297c294,299
< 											$existingElements = t3lib_div::trimExplode(',', $currentValue);
< 											$removeElements = t3lib_div::trimExplode(',', $tsFuncArg);
< 											if (count($removeElements)) {
< 												$newValue = implode(',', array_diff($existingElements, $removeElements));
---
> 											if ($currentValue) {
> 												$existingElements = t3lib_div::trimExplode(',', $currentValue);
> 												$removeElements = t3lib_div::trimExplode(',', $tsFuncArg);
> 												if (count($removeElements)) {
> 													$newValue = implode(',', array_diff($existingElements, $removeElements));
> 												}