我是第一次用EDK9.1，照着技术手册上的例子作了一下，在Generate Netlist的时候，产生了下面的错误，然后plagen 就失败了

*                          HDL Compilation                              *
=========================================================================
Compiling vhdl file "C:/EDK/hw/XilinxProcessorIPLib/pcores/dsocm_v10_v2_00_b/hdl/vhdl/and_or_mux.vhd" in Library dsocm_v10_v2_00_b.
Entity <and_or_mux> compiled.
Entity <and_or_mux> (Architecture <IMP>) compiled.
Compiling vhdl file "C:/EDK/hw/XilinxProcessorIPLib/pcores/dsocm_v10_v2_00_b/hdl/vhdl/dsocm_v10.vhd" in Library dsocm_v10_v2_00_b.
Entity <dsocm_v10> compiled.
Entity <dsocm_v10> (Architecture <IMP>) compiled.
Compiling vhdl file "D:/EDK/hdl/docm_wrapper.vhd" in Library work.
ERROR:HDLParsers:3278 - Can't write file "xst/work/sub00/vhpl00.vho": Permission denied
ERROR:HDLParsers:309 - Can not overwrite the object file in library work.
Entity <docm_wrapper> (Architecture <STRUCTURE>) compiled.
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不知道怎么搞了，有高手指点下没有啊？实在是不行了啊跪求解决方法