[SOLVED, due misclosed custom HTML] Backend editing TABs of item form are missing

But the idea was mine so, that one field open second field is closing. Example <div> in field00 and </div> in field09.
I thank for the devoted time.

Hello

before another field is reached several other HTML tags are open and closed, if you do "view HTML source" you see this, so your idea is impossible

but you can do what you thought in much more powerful way:

1. create 2 new fields of type :
- Tabs / Fieldsets / Custom HTML
and assign them to the desired Item TYPE e.g. to type "Announcement"

2.
Name (=label) 1st field : customDIVopen
Name (=label) 1st field : customDIVclose

then in 1st of them set custom HTML "<div>"
and in 2nd of them set custom HTML "</div>"

2. In Fields manager filter by Item TYPE "Announcement"

3. Order the fields so that you have this order:
...
customDIVopen
myfield1
myfield2
customDIVclose
...

NOTE
- the field above besides custom HTML can also create TAB-sets and Field-sets
- you can use fieldgroup field to create multi-value group of fields