What is the last 4 digits of the MAC for the C1M1? There are 3 different downloads of C1M1 Firmware Updates depending on the Model of C1M1 you have. The C1M1 Utility will not allow you to download the “wrong” firmware into the C1M1:

C1M1 LTEA 0.0.1.8 for the C1M1 LTEA v1

C1M1 LTEV 0.0.1.19 for the C1M1 LTEV v1

C1M1 LTEV 0.0.2.8 for the C1M1 LTEV V2

https://www.elkproducts.com/pro-support-downloads/

Downl0ad all three versions into the X86 directory and try again….