Getting the below exception in our logs but don't see any issues with the code. Anyone faced the same

2018-10-15 18:21:52,815 [ http-bio-80-exec-3] [TABTHREAD0] [ ] [ 7] ( internal.mgmt.Executable) ERROR - Exception
com.pega.pegarules.pub.clipboard.InvalidParameterException: cannot be null. Details: Invalid value for aBasePage passed to com.pega.pegarules.data.internal.clipboard.PropertyReferenceImpl.get(ClipboardPage)
at com.pega.pegarules.data.internal.clipboard.PropertyReferenceImpl.get(PropertyReferenceImpl.java:773) ~[prprivate.jar:?]
at com.pega.pegarules.data.internal.clipboard.PropertyReferenceImpl.get(PropertyReferenceImpl.java:768) ~[prprivate.jar:?]
at com.pega.pegarules.session.internal.mgmt.Executable.getAnyValueViaPropRef(Executable.java:10281) ~[prprivate.jar:?]
at com.pega.pegarules.session.internal.mgmt.Executable.getStringValueViaPropRef(Executable.java:10393) ~[prprivate.jar:?]
at com.pegarules.generated.model.ra_model_assetbilling_bfe999b57a14426f461d77f96ab63b75.updatePage_1(ra_model_assetbilling_bfe999b57a14426f461d77f96ab63b75.java:214) ~[?:?]
at com.pegarules.generated.model.ra_model_assetbilling_bfe999b57a14426f461d77f96ab63b75.perform(ra_model_assetbilling_bfe999b57a14426f461d77f96ab63b75.java:84) ~[?:?]
at com.pega.pegarules.session.internal.mgmt.Executable.applyModel(Executable.java:4534) ~[prprivate.jar:?]
at com.pegarules.generated.activity.ra_action_pxcalldatatransform_9a19c056751333c7b0862218a4b284bb.step1_circum0(ra_action_pxcalldatatransform_9a19c056751333c7b0862218a4b284bb.java:173) ~[?:?]
at com.pegarules.generated.activity.ra_action_pxcalldatatransform_9a19c056751333c7b0862218a4b284bb.perform(ra_action_pxcalldatatransform_9a19c056751333c7b0862218a4b284bb.java:71) ~[?:?]
at com.pega.pegarules.session.internal.mgmt.Executable.doActivity(Executable.java:3586) ~[prprivate.jar:?]
at com.pega.pegarules.exec.internal.declare.infengine.pages.DeclarativePageDirectoryImpl.runRule(DeclarativePageDirectoryImpl.java:1063) ~[prprivate.jar:?]
at com.pega.pegarules.exec.internal.declare.infengine.pages.DeclarativePageDirectoryImpl.runLoadActivity(DeclarativePageDirectoryImpl.java:447) ~[prprivate.jar:?]
at com.pega.pegarules.session.internal.mgmt.base.handler.EditableDataPageHandler.loadDataPage(EditableDataPageHandler.java:129) ~[prprivate.jar:?]
at com.pega.pegarules.session.internal.mgmt.base.handler.EditableDataPageHandler.findDataPage(EditableDataPageHandler.java:296) ~[prprivate.jar:?]
at com.pega.pegarules.session.internal.mgmt.base.AbstractPageDirectory.findDataPageInCurrentDir(AbstractPageDirectory.java:941) ~[prprivate.jar:?]
at com.pega.pegarules.session.internal.mgmt.base.AbstractPageDirectory.getDirectPage(AbstractPageDirectory.java:721) ~[prprivate.jar:?]
at com.pega.pegarules.session.internal.mgmt.base.ThreadPageDir.getDirectPage(ThreadPageDir.java:471) ~[prprivate.jar:?]
at com.pega.pegarules.session.internal.mgmt.base.ThreadPageDir.getPage(ThreadPageDir.java:429) ~[prprivate.jar:?]
at com.pega.pegarules.session.internal.mgmt.PRThreadImpl.getPage(PRThreadImpl.java:559) ~[prprivate.jar:?]
at com.pega.pegarules.session.internal.mgmt.Executable.findPage(Executable.java:2157) ~[prprivate.jar:?]
at com.pega.pegarules.session.internal.mgmt.Executable.findPage(Executable.java:2126) ~[prprivate.jar:?]
at com.pega.pegarules.session.internal.mgmt.Executable.findPage(Executable.java:2104) ~[prprivate.jar:?]
at com.pega.pegarules.session.internal.mgmt.Executable.findPage(Executable.java:2086) ~[prprivate.jar:?]
at com.pegarules.generated.html_section.ra_stream_billingassetstable_8ee0c3f25f7acccc5e3734975ffd3b41.sectionBodyIncludeInCell_3(ra_stream_billingassetstable_8ee0c3f25f7acccc5e3734975ffd3b41.java:576) ~[?:?]
at com.pegarules.generated.html_section.ra_stream_billingassetstable_8ee0c3f25f7acccc5e3734975ffd3b41.simpleLayoutCell_2(ra_stream_billingassetstable_8ee0c3f25f7acccc5e3734975ffd3b41.java:677) ~[?:?]
at com.pegarules.generated.html_section.ra_stream_billingassetstable_8ee0c3f25f7acccc5e3734975ffd3b41.simpleLayout_2(ra_stream_billingassetstable_8ee0c3f25f7acccc5e3734975ffd3b41.java:804) ~[?:?]
at com.pegarules.generated.html_section.ra_stream_billingassetstable_8ee0c3f25f7acccc5e3734975ffd3b41.pzLayoutBodyWrapper_4(ra_stream_billingassetstable_8ee0c3f25f7acccc5e3734975ffd3b41.java:259) ~[?:?]
at com.pegarules.generated.html_section.ra_stream_billingassetstable_8ee0c3f25f7acccc5e3734975ffd3b41.pzLayout_4(ra_stream_billingassetstable_8ee0c3f25f7acccc5e3734975ffd3b41.java:852) ~[?:?]
at com.pegarules.generated.html_section.ra_stream_billingassetstable_8ee0c3f25f7acccc5e3734975ffd3b41.pzSectionBody_1(ra_stream_billingassetstable_8ee0c3f25f7acccc5e3734975ffd3b41.java:244) ~[?:?]
at com.pegarules.generated.html_section.ra_stream_billingassetstable_8ee0c3f25f7acccc5e3734975ffd3b41.execute(ra_stream_billingassetstable_8ee0c3f25f7acccc5e3734975ffd3b41.java:111) ~[?:?]
at com.pega.pegarules.session.internal.mgmt.StreamBuilderTools.appendStreamKeepProperties(StreamBuilderTools.java:776) ~[prprivate.jar:?]
at com.pega.pegarules.session.internal.mgmt.autostreams.IncludeStreamRuntime.getStream(IncludeStreamRuntime.java:332) ~[prprivate.jar:?]
at com.pega.pegarules.session.internal.mgmt.autostreams.IncludeStreamRuntime.emitIncludeStreamReference(IncludeStreamRuntime.java:252) ~[prprivate.jar:?]
at com.pega.pegarules.session.internal.mgmt.autostreams.AutoStreamRuntimeImpl.emitIncludeStreamReference(AutoStreamRuntimeImpl.java:405) ~[prprivate.jar:?]