plugin does not show uninstall /disable button

[thinktodo]

follow as attachment,moduleloader,one plugin does not show uninstall /disable button, but others are ok,what is reason?
my sugar version is 5.2c

[eggsurplus]

I believe it has something to do with the manifest.php file defining it as can't being uninstalled. If you unzip the module and check the manifest.php you may see:

       'is_uninstallable' => false, 
  

If so, this is probably why you are seeing this.