TRP migrated from TW v6.7 to TW v15.5 in Feb2018 and we identified in excess of 50 migration issues. They ranged from cosmetic (a significant number), through minor changes in plugin syntax to a handful of major annoyances. The vast majority had been fixed or worked round before we then applied TW v15.6 over v15.5 in March 2018.
The following items are those that remain a number of weeks after the upgrade to TW15.6. They are probably not bugs in the underlying TW15.6 software, rather issues we've yet to fully understand about TW15.6 and/or our new platform.