I have been using an Asus RT-AC5300 for 4 years and only a few minor hiccups. Merlin firmware was installed. I have 85+ Manually assigned IP addressess. I just bought a gently used identical router for backup reasons. It has Asus firmware 9.0.0.04.386-41994. 2 days I have been trying to upgrade to Merlin. 1. I have downloaded via ethernet not wireless.4 hours of wrong file type. Then saw a fix where change TRX to Capitals CFG. That seemed to work but then when couldnt relog more investigating to an entry ..DO NOT LOG in just hold reset button 5 sec and reboots then try to log in. Well that little exercise leaves me at the asus firmware. Original login. I am getting dizzy from going in circles. I am thinking my next step is target practice. I AM AT THE END OF MY CAPEABILITIES. hELP.