Internal Server Error

com.google.common.util.concurrent.UncheckedExecutionException: java.lang.IllegalArgumentException: invalid URI scheme file
	at com.google.common.cache.LocalCache$Segment.get(LocalCache.java:2199)
	at com.google.common.cache.LocalCache.get(LocalCache.java:3932)
	at com.google.common.cache.LocalCache$LocalManualCache.get(LocalCache.java:4721)
	at info.textgrid.services.aggregator.util.StylesheetManager.getStylesheet(StylesheetManager.java:165)
	at info.textgrid.services.aggregator.html.HTMLWriter.getStylesheet(HTMLWriter.java:207)
	at info.textgrid.services.aggregator.html.HTMLWriter.getTransformer(HTMLWriter.java:233)
	at info.textgrid.services.aggregator.html.HTMLWriter.createResponse(HTMLWriter.java:323)
	at info.textgrid.services.aggregator.REST.getHTML(REST.java:152)
	at jdk.internal.reflect.GeneratedMethodAccessor72.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:303)
	at org.apache.cxf.transport.servlet.AbstractHTTPServlet.doGet(AbstractHTTPServlet.java:221)
	at jakarta.servlet.http.HttpServlet.service(HttpServlet.java:564)
	at org.apache.cxf.transport.servlet.AbstractHTTPServlet.service(AbstractHTTPServlet.java:278)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:195)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:140)
	at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:51)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:164)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:140)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:167)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:90)
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:483)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:116)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:93)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:344)
	at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:398)
	at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:63)
	at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:903)
	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1776)
	at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:52)
	at org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:975)
	at org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:493)
	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:63)
	at java.base/java.lang.Thread.run(Thread.java:840)
Caused by: java.lang.IllegalArgumentException: invalid URI scheme file
	at java.net.http/jdk.internal.net.http.common.Utils.newIAE(Utils.java:310)
	at java.net.http/jdk.internal.net.http.HttpRequestBuilderImpl.checkURI(HttpRequestBuilderImpl.java:82)
	at java.net.http/jdk.internal.net.http.HttpRequestBuilderImpl.uri(HttpRequestBuilderImpl.java:71)
	at java.net.http/jdk.internal.net.http.HttpRequestBuilderImpl.uri(HttpRequestBuilderImpl.java:43)
	at info.textgrid.services.aggregator.util.StylesheetManager$StylesheetLoader.call(StylesheetManager.java:226)
	at info.textgrid.services.aggregator.util.StylesheetManager$StylesheetLoader.call(StylesheetManager.java:180)
	at com.google.common.cache.LocalCache$LocalManualCache$1.load(LocalCache.java:4724)
	at com.google.common.cache.LocalCache$LoadingValueReference.loadFuture(LocalCache.java:3522)
	at com.google.common.cache.LocalCache$Segment.loadSync(LocalCache.java:2315)
	at com.google.common.cache.LocalCache$Segment.lockedGetOrLoad(LocalCache.java:2278)
	at com.google.common.cache.LocalCache$Segment.get(LocalCache.java:2193)
	... 48 more