Since I passed on my E-series DSLRs a few years ago, I can no longer check on what they need, or do.
I think the E-series needs their cards formatted FAT-12, and they can't do that themselves.
I'm referring to a low-level format where the number of bits per entry in the file allocation table, and the sector size (which in the case of a solid-state card would be the basic storage block size, corresponding to the magnetic sectors on a disk) are set-up.
I recall that the E-series can only perform a high-level format, where the data is wiped in each existing sector and also all the entries in the existing FAT.
In the case of putting the card into a computer, they all default to 16-bits per entry in the FAT. You have to specifically change that in the formatting program if you want FAT-12.
I think you need to give that a try.
Oh, one other thing. At the time these things were designed, FAT-12 was the standard, so this issue would never have come up at the time. Right after these things hit the market, there was a shift in the standard from 12 to 16 bits in the FAT. This was to support hard drives that were becoming so large that the sector size was also growing to be too large.
This FAT-12 vs. 16 subject was something that users of older FAT-12 things needed to handle once FAT-16 became the norm. These days, this sort of knowledge is becoming rather arcane. It's only when we try to use something ancient with something modern that we need to recall any of this....
Professional Electronics Development Engineer