The error is indicating that it can not access flash. I would suggest that before you do anything else that you check the flash and make sure that it is correctly seated. It sounds to me like there is a physical issue with accessing flash.
My theory is that the flash is no longer properly seated. If that is true and you re-seat the flash, then it is likely that the image that was in flash before will be in flash again and there will not be a need for Xmodem.
If there is actually no image in flash then you will need something like Xmodem. I would suggest that you check and see if that router supports tftpdnld in rommon. If it is supported it will be much faster in loading the image than Xmodem.
tftpdnld is not supported on 3700 its only on 3800. And as Rickk has suggested check if your flash is seated properly, and more you could try xmodem -r to load the IOS without the flash getting in way.
We are pleased to announce availability of Beta software for 16.6.3.
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towards Catalyst 9500/9400/9300/3850/3650 switching platforms. We are
looking for early feedback from customers befor...
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