linking an insteon device that isn't defined in the config file yet creates error

[marcmerlin]

If I have a device for which I don't know the serial number, I can't define it in the config file, so I link it manually, watch the log file for its serial number, and then add it to the config file later.

But doing this gives:
29/03/2015 13:01:07 [Insteon_PLM] DEBUG2: ALL-Linking Completed with 077e87 (0100077e87020928)
Can't call method "devcat" on an undefined value at ../lib/Insteon_PLM.pm line 927.
at ./mh line 31.
main::ANON("Can't call method "devcat" on an undefined value at ../lib/In"...) called at ../lib/Insteon_PLM.pm line 927
Insteon_PLM::parse_data(Insteon_PLM=HASH(0xaa1ac88), 02530100077e87020928) called at ../lib/Insteon_PLM.pm line 292
Insteon_PLM::check_for_data(Insteon_PLM=HASH(0xaa1ac88)) called at ../lib/Insteon/BaseInterface.pm line 33
Insteon::BaseInterface::check_for_data() called at ./mh line 1409
main::run_hooks("MainLoop_pre") called at (eval 346) line 5
main::MainLoop_pre_hooks() called at ./mh line 1522
main::check_for_action called at ./mh line 3303
main::monitor_commands called at ./mh line 6741