thanks yes, i vaguely remembered that,
but lets assume i never added that plug in, cc [ with default display settings fro a new install] still tries to use composite column details in book details view when linked to cloud, and that's where the issue seems to lie.
one message did flash up, once, on tablet screen, about missing data in composite columns, but I could not get that message to re-appear
my single composite column, was called format: ( now called fmt
had the template #formats.
i think that creates a text string ? of comma separated format names- back in the Calibre details pane, an entry like EPUB, MOBI is clickable but it is a single link , not a pair of links. cc was somehow connecting inaccurate strings to book retails but only in cloud connects. not in content server connects.
and in that respect old version 5.4.4.1 does the same as latest 5.4.1.16, that bit of coding has probably not been touched by the new guys