Of course licorice root does have contraindications and like any herb potential for side effect and harm, but this is a very frequently used herb with known properties. Still, it's good to be aware of this possibility.
A study of mold/mycotoxins on medicinal plants from Pakistan produced some troubling findings, including for licorice root. This once again shows the importance of using quality sources who understand and adhere to best practices. Evaluation of mycotoxins, mycobiota, and toxigenic fungi in selected medicinal plants of Khyber Pakhtunkhwa, Pakistan. https://www.ncbi.nlm.nih.gov/pubmed/25209636
"Opium poppy, licorice root, and Indian rennet were most contaminated samples."