[scb]

You didn't ask for Keyboard Maestro output, but activate does not work from Keyboard Maestro as of OmniFocus 95014. Here is the debug output:

AE2000 (584): Received an event:
------oo start of event oo------
{ 1 } 'aevt':  misc/actv (i386){
          return id: 13238293 (0xca0015)
     transaction id: 0 (0x0)
  interaction level: 112 (0x70)
     reply required: 1 (0x1)
             remote: 0 (0x0)
      for recording: 0 (0x0)
         reply port: 40743 (0x9f27)
  target:
    { 1 } 'psn ':  8 bytes {
      { 0x0, 0x19019 } (Keyboard Maestro)
    }
  fEventSourcePSN: { 0x0,0x19019 } (Keyboard Maestro)
  optional attributes:
    { 1 } 'reco':  - 2 items {
      key 'subj' - 
        { -1 } 'null':  null descriptor
      key 'csig' - 
        { 1 } 'magn':  4 bytes {
          65536l (0x10000)
        }
    }

  event data:
    { 1 } 'aevt':  - 0 items {
    }
}

------oo  end of event  oo------

In comparison, here's the output when the script is invoked from the Script Menu:

AE2000 (584): Received an event:
------oo start of event oo------
{ 1 } 'aevt':  misc/actv (i386){
          return id: 38469634 (0x24b0002)
     transaction id: 0 (0x0)
  interaction level: 96 (0x60)
     reply required: 1 (0x1)
             remote: 0 (0x0)
      for recording: 0 (0x0)
         reply port: 40967 (0xa007)
  target:
    { 1 } 'psn ':  8 bytes {
      { 0x0, 0x4f04f } (AppleScript Runner)
    }
  fEventSourcePSN: { 0x0,0x4f04f } (AppleScript Runner)
  optional attributes:
    { 1 } 'reco':  - 2 items {
      key 'subj' - 
        { -1 } 'null':  null descriptor
      key 'csig' - 
        { 1 } 'magn':  4 bytes {
          65536l (0x10000)
        }
    }

  event data:
    { 1 } 'aevt':  - 1 items {
      key '----' - 
        { -1 } 'null':  null descriptor
    }
}

------oo  end of event  oo------