Catching System.Exception seems like an efficient way to handle multiple possible exceptions. Unfortunately, it traps all exception types, including the ones that were not intended to be caught. To prevent any misunderstandings, the exception filters should be used. Alternatively each exception type should be in a separate catch block.

Noncompliant Code Example

try
{
  // do something that might throw a FileNotFoundException or IOException
}
catch (Exception e) // Noncompliant
{
  // log exception ...
}

Compliant Solution

try
{
  // do something
}
catch (Exception e) when (e is FileNotFoundException || e is IOException)
{
  // do something
}

Exceptions

The final option is to catch System.Exception and throw it in the last statement in the catch block. This is the least-preferred option, as it is an old-style code, which also suffers from performance penalty compared to exception filters.

try
{
  // do something
}
catch (Exception e)
{
  if (e is FileNotFoundException || e is IOException)
  {
    // do something
  }
  else
  {
    throw;
  }
}

See