It looks like you have loaded an image which requires more DRAM than your router has installed. A simple solution would be to change to a bigger memory module (DRAM not Flash) or to install a smaller image, depends which one you have available.
The error message does indicate that you could try removing one of the modules to free up some memory, have you tried this ?
The ? file name may just be that you put in a blank destination filename when uploading the image ?
We are pleased to announce availability of Beta software for 16.6.3. 16.6.3 will be the second rebuild on the 16.6 release train targeted towards Catalyst 9500/9400/9300/3850/3650 switching platforms. We are looking for early feedback from custome...