Font in .otf format

I am using **OCR-B-Regular.otf** font. But I am getting the following error:

> java.lang.NullPointerException: null
at com.openhtmltopdf.pdfboxout.PdfBoxTextRenderer.getWidth(PdfBoxTextRenderer.java:300)
at com.openhtmltopdf.render.InlineBox.getSpaceWidth(InlineBox.java:221)
at com.openhtmltopdf.render.InlineBox.calcMinWidthFromWordLength(InlineBox.java:238)
at com.openhtmltopdf.render.InlineBox.calcMinMaxWidth(InlineBox.java:378)
at com.openhtmltopdf.render.BlockBox.calcMinMaxWidthInlineChildren(BlockBox.java:1748)
at com.openhtmltopdf.render.BlockBox.calcMinMaxWidth(BlockBox.java:1624)
at com.openhtmltopdf.render.BlockBox.calcShrinkToFitWidth(BlockBox.java:1501)
at com.openhtmltopdf.render.BlockBox.calcShrinkToFitWidthIfNeeded(BlockBox.java:976)
at com.openhtmltopdf.render.BlockBox.layout(BlockBox.java:869)
at com.openhtmltopdf.render.BlockBox.layout(BlockBox.java:823)
at com.openhtmltopdf.layout.InlineBoxing.layoutInlineBlockContent(InlineBoxing.java:426)
at com.openhtmltopdf.layout.InlineBoxing.layoutContent(InlineBoxing.java:317)
at com.openhtmltopdf.render.BlockBox.layoutInlineChildren(BlockBox.java:1068)
at com.openhtmltopdf.render.BlockBox.layoutChildren(BlockBox.java:1049)
at com.openhtmltopdf.render.BlockBox.layout(BlockBox.java:906)
at com.openhtmltopdf.render.BlockBox.layout(BlockBox.java:823)
at com.openhtmltopdf.layout.BlockBoxing.layoutBlockChild0(BlockBoxing.java:321)
at com.openhtmltopdf.layout.BlockBoxing.layoutBlockChild(BlockBoxing.java:299)
at com.openhtmltopdf.layout.BlockBoxing.layoutContent(BlockBoxing.java:90)
at com.openhtmltopdf.render.BlockBox.layoutChildren(BlockBox.java:1052)
at com.openhtmltopdf.render.BlockBox.layout(BlockBox.java:906)
at com.openhtmltopdf.render.BlockBox.layout(BlockBox.java:823)
at com.openhtmltopdf.layout.Layer.layoutAbsoluteChild(Layer.java:1014)
at com.openhtmltopdf.layout.Layer.layoutAbsoluteChildren(Layer.java:949)
at com.openhtmltopdf.layout.Layer.finish(Layer.java:935)
at com.openhtmltopdf.layout.LayoutContext.popLayer(LayoutContext.java:306)
at com.openhtmltopdf.render.BlockBox.layout(BlockBox.java:948)
at com.openhtmltopdf.render.BlockBox.layout(BlockBox.java:823)
at com.openhtmltopdf.pdfboxout.PdfBoxRenderer.layout(PdfBoxRenderer.java:333)
at com.openhtmltopdf.pdfboxout.PdfRendererBuilder.run(PdfRendererBuilder.java:40)

Is it possible to use .otf fonts ?