If "Vertical Arrangement" is chosen, setting one of the panel widths to 0% also causes Tab to switch to hidden tab in the 32bit version as well as the 64bit version.
License #524 (1994)
Danish Total Commander Translator
TC 11.51 32+64bit on Win XP 32bit & Win 7, 8.1 & 10 (22H2) 64bit, 'Everything' 1.5.0.1391a
TC 3.60b4 on Android 6, 13, 14 TC Extended Menus | TC Languagebar | TC Dark Help | PHSM-Calendar
2ghisler(Author)
I reported the bug in TC x64 only, correct. It seems you missed Peter's post that this bug occurs in TC 32 bit, too, when vertical arrangement is enabled.
Regards
Dalai
#101164 Personal licence
Ryzen 5 2600, 16 GiB RAM, ASUS Prime X370-A, Win7 x64
2petermad
No, the vertical arrangement bug was not fixed before beta4. Set the panel width to something between ~95 and 99.5% (with vertical arrangement): TC still switches to the smaller panel, although the user can't see anything in there. Hence the history.txt states:
29.06.16 Fixed: Vertical file panel arrangement: Don't allow tab to panel where nothing of the list window is visible (32/64)
Regards
Dalai
#101164 Personal licence
Ryzen 5 2600, 16 GiB RAM, ASUS Prime X370-A, Win7 x64