This bug goes as far as the option itself (8.50), but was revealed only recently on a Russian forum.
1. Set VerifyEnabled=0 in wincmd.ini. Open TC, Settings, Copy/Delete.
2. There are now 3 checkboxes in the bottom group "General Copy+Delete options", the "MD5" one is missing, which is normal.
3. Change any option in this dialog and click Apply.
4. The "Use Explorer delete" checkbox in that group suddenly disappears; now there are only 2 checkboxes!
[Old] VerifyEnabled=0 causes unrelated options to disappear
Moderators: Hacker, petermad, Stefan2, white
[Old] VerifyEnabled=0 causes unrelated options to disappear
Flint's Homepage: Full TC Russification Package, VirtualDisk, NTFS Links, NoClose Replacer, and other stuff!
Using TC 11.03 / Win10 x64
Using TC 11.03 / Win10 x64
Re: [Old] VerifyEnabled=0 causes unrelated options to disappear
Confirmed for both 32bit and 64bit TC
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
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
Re: [Old] VerifyEnabled=0 causes unrelated options to disappear
Seems fixed in 9.50β4.
Flint's Homepage: Full TC Russification Package, VirtualDisk, NTFS Links, NoClose Replacer, and other stuff!
Using TC 11.03 / Win10 x64
Using TC 11.03 / Win10 x64
Re: [Old] VerifyEnabled=0 causes unrelated options to disappear
Confirmed fixed in TC 9.5b4 
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
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