thinkphp 3.1 return XML format for unprovoked end

The method code has only the following

   echo 'hello';exit();

Chrome viewing HTTP response results in the following:
Content-type:image/svg+xml

Add before output

header('Content-type:text/html;charset=utf-8');

The output is normal
Others page Most normal, occasionally will appear above error, what solution

Reply content:

The method code has only the following

   echo 'hello';exit();

Chrome viewing HTTP response results in the following:
Content-type:image/svg+xml

Add before output

header('Content-type:text/html;charset=utf-8');

The output is normal
Others page Most normal, occasionally will appear above error, what solution

If the impact of development is not as good as changing 3.2 (: 3"∠)

Change 3.2.2 Try Bai, now 5.0 are out, don't use 3.1

