Of course I've checked Nika's procedure but there weren't any duplicate entries in tables which could cause this.
After running queries like
select * from cmn_option_values
order by last_updated_date desc
select * from cmn_options
where option_code like '%FIN.RES_PLAN_USE_LABOR_ONLY%'
In first case I didn't find any record in table from today, in second case I didn't find anything
So I then run insert SP from error log above:
exec CMN_OPTIONS_INS_SP('FIN.RES_PLAN_USE_LABOR_ONLY', 'FIN.RES_PLAN_USE_LABOR_ONLY', 'FIN.RES_PLAN_USE_LABOR_ONLY', 1,1,1);
exec CMN_OPTION_VALUES_INS_SP('FIN.RES_PLAN_USE_LABOR_ONLY', NULL, NULL, '0', 1);
Checked both tables, records were in, then run installer and Patch 14 has been finally installed successfully
Hopefully this will help to someone else. I'd like to also say Thank you a lot for your help, Suman.
Matej