HPCC-10545 Fix obscure problem causing dataset not active error

Signed-off-by: Gavin Halliday <gavin.halliday@lexisnexis.com>
Merge pull request #5219 from ghalliday/issue10545

HPCC-10545 Fix obscure problem causing dataset not active error

Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>