so it seems:
https://community.st.com/t5/stm32-mcus-embedded-software/sd-card-no-file-system-error/m-p/641421/highlight/true#M45513
On other forums, the 'Mark As Solution' just changes to 'Unmark Solution' (or whatever) - so it's always obvious, and in the same place.
Addendum:
Perhaps this:
https://community.st.com/t5/stm32-mcus-embedded-software/sd-card-no-file-system-error/m-p/641422/highlight/true#M45514
could be added here:
https://community.st.com/t5/community-guidelines/help-others-to-solve-their-issues/ta-p/575256
A complex system that works is invariably found to have evolved from a simple system that worked.
A complex system designed from scratch never works and cannot be patched up to make it work.
