I suspect you're encountering the same issue that was recently reported in this forum regarding C++ errors when attempting a STEP translation. Your Windows OS was likely recently updated, which caused changes to your graphics driver and those changes are preventing you from completing your translations.
The most reliable workaround appears to be to uninstall/reinstall your current graphics card driver (or uninstall and reinstall the certified driver). You can find more information here and here. If you continue to experience problems please call your local GTAC office.