There is a boot-sector bug in the control software for the Exterior 600, MAC 250, MAC 300, and Pro 918 that disables upload mode if a software upload gets interrupted. If this happens, upload mode must be manually enabled by setting the jumper at PL121 to the INIT position.

This bug will be fixed in the next software update for each of the effected products. We STRONGLY recommend that the boot sector update be performed with next service of the fixture or before installation of new fixtures.