500: Unexpected server error

A failure occurred during LabKey Server startup.

java.lang.NoSuchMethodError: org.labkey.api.ehr.EHRService.registerSimpleFormType(Lorg/labkey/api/ehr/EHRService$FORM_TYPE;Lorg/labkey/api/module/Module;Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;)V
       at org.labkey.onprc_ehr.ONPRC_EHRModule.registerEHRResources(ONPRC_EHRModule.java:184)
       at org.labkey.onprc_ehr.ONPRC_EHRModule.doStartupAfterSpringConfig(ONPRC_EHRModule.java:103)
       at org.labkey.api.ldk.ExtendedSimpleModule.startupAfterSpringConfig(ExtendedSimpleModule.java:79)
       at org.labkey.api.module.SpringModule.doStartup(SpringModule.java:119)
       at org.labkey.api.module.DefaultModule.startup(DefaultModule.java:273)
       at org.labkey.api.module.ModuleLoader.ensureStartupComplete(ModuleLoader.java:874)
       at org.labkey.api.module.ModuleLoader.doFilter(ModuleLoader.java:797)
       at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
       at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
       at org.labkey.api.security.AuthFilter.doFilter(AuthFilter.java:171)
       at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
       at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
       at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
       at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
       at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
       at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
       at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
       at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)
       at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:859)
       at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:602)
       at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
       at java.lang.Thread.run(Thread.java:722)