Fixed (v6.44+dev0107)
I offlined the file with Item: Set all media offline prior to trying to delete the .reapindex file.
Is this intended?
(Probably doesn't affect anything except this special case I was looking into handling (deleting, edit: actually moving) old .reapindex files with SWS action: 'Xenakios/SWS: Rename take source files...', works with .reapeaks files as they are released when media is set offline, but not with .reapindex files because above).