Exception handling F#从lexer捕获异常

我试图让我的F#代码从lexer捕获一个输入错误的异常。尽管引发了异常，但另一个模块未捕获该异常。有人能帮忙吗

let lexstring expr =
    try
        LexBuffer<char>.FromString(expr)
    with 
     Lexer.IllegalCharacter  -> failwith "XXXXXXXXXXXX" 

错误消息如下所示：

Lexer.IllegalCharacter occurred
  HResult=-2146233088
  Message=Exception of type 'Lexer+IllegalCharacter' was thrown.
  Source=FSharp.Core
  StackTrace:
       at Microsoft.FSharp.Core.Operators.Raise[T](Exception exn)
       at Lexer._fslex_tokenize(Int32 _fslex_state, LexBuffer`1 lexbuf) in E:\Programming\F#\fsapp_ozan\parser\Lexer.fsl:line 48
  InnerException: 

---

您是否尝试捕获所有异常以查看得到的结果？是否可以发布“其他模块”中的代码？这是visual studio的一个问题。现在问题解决了，但我不知道怎么解决。

Lexer.IllegalCharacter occurred
  HResult=-2146233088
  Message=Exception of type 'Lexer+IllegalCharacter' was thrown.
  Source=FSharp.Core
  StackTrace:
       at Microsoft.FSharp.Core.Operators.Raise[T](Exception exn)
       at Lexer._fslex_tokenize(Int32 _fslex_state, LexBuffer`1 lexbuf) in E:\Programming\F#\fsapp_ozan\parser\Lexer.fsl:line 48
  InnerException: