I was on prince of apocalypse and other maps and if your a player and you hit the delete option it deletes everything and you cant see that map

exactly what the topic title says

If you delete your token, then you are no longer "on" the map, and have no way to see the map. You need to drag another token out to the VTT (or ask your GM to do so for you).

VTT? can you say what the abbreviation of that is im unfamiliar with it

Virtual Table Top. Roll20 is a Virtual Table Top system. 

I.e. The "map area" or the "play area".

I try to pull a character back into it and they are still see black do i have to make another character for them 

Is the default token set to have sight and light or nightvision? If the default token was last saved when those were not active, it will not have it on any subsequent drags. Your GM must set your vision settings and then save the default in order for you to be able to see at the time the token is placed.

In addition to what Keith is saying, when you make changes to a token, you are only making changes to the exact copy of the token.  You have to then save it to their sheet, at which time all future drags will have those changes, but other copies on other pages that were created before saving the changes will not have the changes.

Patrick said: In addition to what Keith is saying, when you make changes to a token, you are only making changes to the exact copy of the token.  You have to then save it to their sheet, at which time all future drags will have those changes, but other copies on other pages that were created before saving the changes will not have the changes. This comes up quite often, because DMs don't realise that when they are dragging from a character sheet to the map then a COPY of the token is created on the map - it is NOT the token that is stored as part of the character sheet.

the character that is pulled has nightvision

another question about dynamic lighting it sometimes bugs out is their ways of fixing it and what i mean by that is it does not save when you turn it on in the settings and i have to keep doing it any advice on that