You have database connection on the label and you are using record selection option and some filter probably. Unfortunately in such combination NiceLabel 188.8.131.525 reports an error message: "External exception: EEFFACE".
The bug fix is available here
Please replace Epds5.dll file located at "c:\Program Files\Common Files\EuroPlus Shared\".
Note: this is a temporary solution. The fix will be included in next forthcoming NiceLabel build. Please install it when it will be available.