Help with attempt to index nil errors

I need help I have several scripts saying the same thing

login:10: attempt to index ? (a nil value)

how can I get this fixed

Spoiler

term.clear()
term.setCursorPos(20,3)
print("Login System")
term.setCursorPos(1,6)

term.setCursorPos(10,8)
print("Name: ")
term.setCursorPos(10,10)
print("Password: ")
term.setCursorPos(20,8)
name = read()
term.setCursorPos(20,10)
pass = read()

login = ""



dbp = io.open("DB/DBlog/" ..name)
if dbp
then
corpass = dbp:read()
dbp:close()
if pass == corpass
then
login = "good"
end
end

sleep(1)
term.clear()
term.setCursorPos(20,3)
print("Login System")
term.setCursorPos(1,6)
if login == "good"
then
print("login accepted" )
end

if login == "good"
then
DBcn = io.open("DB/DBcur/name", "w")
DBcn:write(name)
DBcn:close()

DBl = io.open("DB/DBlvl/"..name, "r")
lvl = DBl:read()
DBl:close()

DBcl = io.open("DB/DBcur/level", "w")
DBcl:write(lvl)
DBcl:close()
end

sleep(1)

Create:28: attempt to index ? (a nil value)

Spoiler

term.clear()
term.setCursorPos(18,3)
print("Account Creation")

term.setCursorPos(10,8)
write("Name: ")
term.setCursorPos(10,10)
write("Password: ")
term.setCursorPos(20,8)
name = read()
term.setCursorPos(20,10)
pass = read()

term.setCursorPos(5,12)

dbp = io.open("DB/DBlog/"..name, "r")
if dbp
then
dbp:close()
print("Username already exists")
sleep(1)
term.setCursorPos(5,13)
print("Shutting down now")
sleep(1.5)
os.shutdown()
else
dbp = io.open("DB/DBlog/"..name, "w")
dbp:write(pass)
dbp: close()

dbl = io.open("DB/DBlvl/"..name, "w")
dbl:write("1")
dbl:close()

print("New account created")
sleep(1)
term.setCursorPos(5,13)
print("ending session")
sleep(1.5)
os.shutdown()
end

any help is appreciated

Split into new topic.

The stated errors don't match with the errors the code would actually throw if you ran it. If you re-typed it here, please re-check it, character for character, to ensure that it is a complete match for what is in the actual computer.

Also, please make sure that all the folders you're using (/DB, /DB/DBlog, etc.) actually exist.