Internal Server Error

com.google.common.util.concurrent.UncheckedExecutionException: java.lang.IllegalArgumentException: invalid URI scheme file
	at com.google.common.cache.LocalCache$Segment.get(LocalCache.java:2074)
	at com.google.common.cache.LocalCache.get(LocalCache.java:3986)
	at com.google.common.cache.LocalCache$LocalManualCache.get(LocalCache.java:4855)
	at info.textgrid.services.aggregator.util.StylesheetManager.getStylesheet(StylesheetManager.java:169)
	at info.textgrid.services.aggregator.html.HTMLWriter.getStylesheet(HTMLWriter.java:204)
	at info.textgrid.services.aggregator.html.HTMLWriter.getTransformer(HTMLWriter.java:230)
	at info.textgrid.services.aggregator.html.HTMLWriter.createResponse(HTMLWriter.java:325)
	at info.textgrid.services.aggregator.REST.getHTML(REST.java:152)
	at jdk.internal.reflect.GeneratedMethodAccessor66.invoke(Unknown Source)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:569)
	at org.apache.cxf.service.invoker.AbstractInvoker.performInvocation(AbstractInvoker.java:179)
	at org.apache.cxf.service.invoker.AbstractInvoker.invoke(AbstractInvoker.java:96)
	at org.apache.cxf.jaxrs.JAXRSInvoker.invoke(JAXRSInvoker.java:200)
	at org.apache.cxf.jaxrs.JAXRSInvoker.invoke(JAXRSInvoker.java:103)
	at org.apache.cxf.interceptor.ServiceInvokerInterceptor$1.run(ServiceInvokerInterceptor.java:59)
	at org.apache.cxf.interceptor.ServiceInvokerInterceptor.handleMessage(ServiceInvokerInterceptor.java:96)
	at org.apache.cxf.phase.PhaseInterceptorChain.doIntercept(PhaseInterceptorChain.java:307)
	at org.apache.cxf.transport.ChainInitiationObserver.onMessage(ChainInitiationObserver.java:121)
	at org.apache.cxf.transport.http.AbstractHTTPDestination.invoke(AbstractHTTPDestination.java:267)
	at org.apache.cxf.transport.servlet.ServletController.invokeDestination(ServletController.java:233)
	at org.apache.cxf.transport.servlet.ServletController.invoke(ServletController.java:207)
	at org.apache.cxf.transport.servlet.ServletController.invoke(ServletController.java:159)
	at org.apache.cxf.transport.servlet.CXFNonSpringServlet.invoke(CXFNonSpringServlet.java:224)
	at org.apache.cxf.transport.servlet.AbstractHTTPServlet.handleRequest(AbstractHTTPServlet.java:312)
	at org.apache.cxf.transport.servlet.AbstractHTTPServlet.doGet(AbstractHTTPServlet.java:222)
	at jakarta.servlet.http.HttpServlet.service(HttpServlet.java:564)
	at org.apache.cxf.transport.servlet.AbstractHTTPServlet.service(AbstractHTTPServlet.java:279)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:197)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:142)
	at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:57)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:166)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:142)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:165)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:88)
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:535)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:115)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:86)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:71)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:348)
	at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:408)
	at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:71)
	at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:1307)
	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:2032)
	at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:74)
	at org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:976)
	at org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:494)
	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:80)
	at java.base/java.lang.Thread.run(Thread.java:840)
Caused by: java.lang.IllegalArgumentException: invalid URI scheme file
	at java.net.http/jdk.internal.net.http.common.Utils.newIAE(Utils.java:310)
	at java.net.http/jdk.internal.net.http.HttpRequestBuilderImpl.checkURI(HttpRequestBuilderImpl.java:82)
	at java.net.http/jdk.internal.net.http.HttpRequestBuilderImpl.uri(HttpRequestBuilderImpl.java:71)
	at java.net.http/jdk.internal.net.http.HttpRequestBuilderImpl.uri(HttpRequestBuilderImpl.java:43)
	at info.textgrid.services.aggregator.util.StylesheetManager$StylesheetLoader.call(StylesheetManager.java:231)
	at info.textgrid.services.aggregator.util.StylesheetManager$StylesheetLoader.call(StylesheetManager.java:184)
	at com.google.common.cache.LocalCache$LocalManualCache$1.load(LocalCache.java:4860)
	at com.google.common.cache.LocalCache$LoadingValueReference.loadFuture(LocalCache.java:3551)
	at com.google.common.cache.LocalCache$Segment.loadSync(LocalCache.java:2302)
	at com.google.common.cache.LocalCache$Segment.lockedGetOrLoad(LocalCache.java:2177)
	at com.google.common.cache.LocalCache$Segment.get(LocalCache.java:2068)
	... 48 more