開啟VS的【工具】-【選項】-【除錯】-【符號】
1、先取消勾選“Microsoft符號伺服器”
2、清空符號快取

3、重啟VS

試試VS官方論壇上提到的解決方法：
You can speed up loading of symbols by doing the following:
1. Verify
that you haven’t specified any network shares under
Tools->Options->Debugging->Symbols especially to server that do not
exist anymore. This will require timeouts.
2. Verify and check that
_NT_SYMBOL_PATH or _NT_ALT_SYMBOL_PATH is set to network shares as cg60611
pointed out above.
3. Specify a local cache for symbols in
Tools->Options->Debugging->Symbols. After you have downloaded symbols
once from network shares you can disable those locations. Symbol loading will go
a lot faster after the first attempt.
4. Do not specify any symbol lookup
paths at all eithe in environment variable and specify paths in the options page
but specify that they be used for manual loading. You can then manually load
symbols for modules you care about either via the context menu in callstack or
the modules window.
5. VS 2008 SP1 has made a few improvements in this
area. It allows for cancelling loading of symbols as it is happening. This will
allow you to get to your debug session much faster. Note that this is currently
in Beta.