I need Tomcat to map the local resource path, but start the error message after configuration: the specified main resource set is invalid

Environment configuration:

1.jdk:1.8
2.tomcat:9.0
3.:windows servers 2008 r2

this is the mapping configuration in my server.xml:

<Context docBase="C:\upload" path="/upload" debug="0" reloadable="true" />

method I have tried:

1.C:\upload
2.startup.bat
3.tomcatweb.xmllistenstrue,
4.server.xml

error message:
26-Feb-2019 10 main 56 org.apache.catalina.startup.Catalina.start service components required by serious [main] org.apache.catalina.startup.Catalina.start failed to start, so Tomcat could not be started
org.apache.catalina.LifecycleException: child container startup failed

at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:926)
at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:262)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
at org.apache.catalina.core.StandardService.startInternal(StandardService.java:423)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:933)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
at org.apache.catalina.startup.Catalina.start(Catalina.java:637)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:350)
at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:492)

Caused by: java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: child container startup failed

at java.util.concurrent.FutureTask.report(FutureTask.java:122)
at java.util.concurrent.FutureTask.get(FutureTask.java:192)
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:914)
... 13 more

Caused by: org.apache.catalina.LifecycleException: child container startup failed

at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:926)
at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:831)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1382)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1372)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75)
at java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:134)
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:907)
... 13 more

Caused by: java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [org.apache.catalina.webresources.StandardRoot@50d0686]

at java.util.concurrent.FutureTask.report(FutureTask.java:122)
at java.util.concurrent.FutureTask.get(FutureTask.java:192)
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:914)
... 21 more

Caused by: org.apache.catalina.LifecycleException: Failed to start component [org.apache.catalina.webresources.StandardRoot@50d0686]

at org.apache.catalina.util.LifecycleBase.handleSubClassException(LifecycleBase.java:441)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:198)
at org.apache.catalina.core.StandardContext.resourcesStart(StandardContext.java:4778)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:4913)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1382)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1372)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75)
at java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:134)
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:907)
... 21 more

Caused by: java.lang.IllegalArgumentException: the specified main resource set [C:upload] is invalid

at org.apache.catalina.webresources.StandardRoot.createMainResourceSet(StandardRoot.java:749)
at org.apache.catalina.webresources.StandardRoot.startInternal(StandardRoot.java:706)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
... 30 more

is there a god to save the child? there is no result after adjusting it for a long time!