I have been trying to record sucessfully these last days on my Formuler 7+
Everything went allright as long as i used a small SD card of 4GB.
When i tried to use a 256GB or even a 64GB SD card, it was accepted but failed sooner or later.
Eventually i found out that if the Card has a capacity of 32GB or smaller it works.
And why ?
Because you can format it as a FAT32 using any Windows PC.
An if its bigger ?
It works if you format it as NTFS, but NOT the Windows exFAT default.
I suggest that this information should be very clear at the Formuler TV site, at the Formiuler 7+ specifications.
Also the maximum SD card size supported should be specified.
That could avoid a lot of frustration for some users.
Up to now, i tried a 4GB SD (FAT32) and a 64GB, 128GB and 256GB SD's (NTFS). All worked.