If change our plugin to ZIP and uncompress it, we can see that for linux-32 we have folder "Linux x86".
If change to "Linux X86" -- then Xojo is happy.
Strange is that we have small case for years, and with sure there was developer which did compile for linux-32... So it seems something was changed in Xojo.
In ideal they should recognize both...
anyway we have fix name of folder in our scripts, and next build will have this fix.