I ended up downloading the file again and it worked as planned. Same download path, same file name. Must have just gotten a bad download the first time around.
I'm trying to upgrade my 8100 stack ((1) 8164 & (1) 8132) but I'm not seeing the backup image version change. I'm following the instructions included with the firmware, currently show version lists the backup and active versions as 5.1.0.1. If I upload the new version using copy txxx.xxx.xxx.xxx/N4000v6.1.2.4.stk backup the file uploads and copies to the second switch successfully but show version still lists the backup version as 5.1.0.1. I've even tried removing the backup file first which then shows as none under backup in show version. Then uploaded 6.1.2.4 again as backup but show version still lists it as 5.1.0.1.  Any ideas what I can do to get 6.1.2.4 loaded?
8100 upgrade 5.1.0.1->6.1.2.4