I use javax.xml.transform.TransformerFactory to transform data with xsl stylesheet. XPage is not rendered and the code is in 'afterRenderResponse'. When I tick 'com.ibm.xsp.extlib.library' library in 'XSP Properties' file, the tranformation is more then 3 times slower. When I was using Domino 8.5 with ExtLib, it was ok, but when i upgraded to domino 9.0.1 (FP9) this problem have began. It It is still after upgraded to extlib (9.0.1_v09_02_20171023-1055). Thank you for your help. Tom