<s>
An	O
error	B-Error_Name
message	I-Error_Name
is	O
information	O
displayed	O
when	O
an	O
unforeseen	O
problem	O
occurs	O
,	O
usually	O
on	O
a	O
computer	B-General_Concept
or	O
other	O
device	O
.	O
</s>
<s>
On	O
modern	O
operating	B-General_Concept
systems	I-General_Concept
with	O
graphical	B-Application
user	I-Application
interfaces	I-Application
,	O
error	B-Error_Name
messages	I-Error_Name
are	O
often	O
displayed	O
using	O
dialog	O
boxes	O
.	O
</s>
<s>
Error	B-Error_Name
messages	I-Error_Name
are	O
used	O
when	O
user	O
intervention	O
is	O
required	O
,	O
to	O
indicate	O
that	O
a	O
desired	O
operation	O
has	O
failed	O
,	O
or	O
to	O
relay	O
important	O
warnings	O
(	O
such	O
as	O
warning	O
a	O
computer	B-General_Concept
user	O
that	O
they	O
are	O
almost	O
out	O
of	O
hard	B-Device
disk	I-Device
space	O
)	O
.	O
</s>
<s>
Error	B-Error_Name
messages	I-Error_Name
are	O
seen	O
widely	O
throughout	O
computing	O
,	O
and	O
are	O
part	O
of	O
every	O
operating	B-General_Concept
system	I-General_Concept
or	O
computer	B-Architecture
hardware	I-Architecture
device	O
.	O
</s>
<s>
Proper	O
design	B-Error_Name
of	I-Error_Name
error	I-Error_Name
messages	I-Error_Name
is	O
an	O
important	O
topic	O
in	O
usability	B-General_Concept
and	O
other	O
fields	O
of	O
human	O
–	O
computer	B-General_Concept
interaction	O
.	O
</s>
<s>
The	O
following	O
error	B-Error_Name
messages	I-Error_Name
are	O
commonly	O
seen	O
by	O
modern	O
computer	B-General_Concept
users	O
:	O
</s>
<s>
This	O
error	O
occurs	O
if	O
the	O
user	O
does	O
n't	O
have	O
privileges	O
to	O
a	O
file	B-Operating_System
,	O
or	O
if	O
it	O
has	O
been	O
locked	B-Application
by	O
some	O
program	O
or	O
user	O
.	O
</s>
<s>
This	O
error	O
most	O
often	O
occurs	O
when	O
there	O
is	O
no	O
floppy	B-Device
disk	I-Device
(	O
or	O
a	O
bad	O
disk	O
)	O
in	O
the	O
disk	O
drive	O
and	O
the	O
system	O
tries	O
to	O
perform	O
tasks	O
involving	O
this	O
disk	O
.	O
</s>
<s>
The	O
file	B-Operating_System
concerned	O
may	O
have	O
been	O
damaged	O
,	O
moved	O
,	O
deleted	O
,	O
or	O
a	O
bug	B-Error_Name
may	O
have	O
caused	O
the	O
error	O
.	O
</s>
<s>
Alternatively	O
,	O
the	O
file	B-Operating_System
simply	O
might	O
not	O
exist	O
,	O
or	O
the	O
user	O
has	O
mistyped	O
its	O
name	O
.	O
</s>
<s>
On	O
a	O
local	O
computer	B-General_Concept
,	O
this	O
is	O
more	O
frequent	O
on	O
command	B-Application
line	I-Application
interfaces	I-Application
than	O
on	O
graphical	B-Application
user	I-Application
interfaces	I-Application
where	O
files	O
are	O
presented	O
iconically	O
and	O
users	O
do	O
not	O
type	O
file	B-Operating_System
names	O
.	O
</s>
<s>
This	O
error	O
occurs	O
when	O
the	O
hard	B-Device
drive	I-Device
is	O
(	O
nearly	O
)	O
full	O
.	O
</s>
<s>
To	O
fix	O
this	O
,	O
the	O
user	O
should	O
close	O
some	O
programs	O
(	O
to	O
free	O
swap	B-Architecture
file	I-Architecture
usage	O
)	O
and	O
delete	O
some	O
files	O
(	O
normally	O
temporary	O
files	O
,	O
or	O
other	O
files	O
after	O
they	O
have	O
been	O
backed	O
up	O
)	O
,	O
or	O
get	O
a	O
bigger	O
hard	B-Device
drive	I-Device
.	O
</s>
<s>
This	O
error	O
occurs	O
when	O
the	O
system	O
has	O
run	O
out	O
of	O
memory	O
or	O
tries	O
to	O
load	O
a	O
file	B-Operating_System
too	O
large	O
to	O
store	O
in	O
RAM	B-Architecture
.	O
</s>
<s>
This	O
message	O
and	O
similar	O
ones	O
are	O
displayed	O
by	O
several	O
operating	B-General_Concept
systems	I-General_Concept
when	O
program	O
causes	O
a	O
general	B-Operating_System
protection	I-Operating_System
fault	I-Operating_System
or	O
invalid	O
page	B-General_Concept
fault	I-General_Concept
.	O
</s>
<s>
The	O
Blue	O
Screen	O
of	O
Death	O
-	O
On	O
Microsoft	O
Windows	O
and	O
ReactOS	O
operating	B-General_Concept
systems	I-General_Concept
,	O
this	O
screen	O
appears	O
when	O
Windows	O
or	O
ReactOS	O
can	O
no	O
longer	O
run	O
because	O
of	O
a	O
severe	O
error	O
.	O
</s>
<s>
It	O
is	O
roughly	O
analogous	O
to	O
a	O
kernel	B-Operating_System
panic	I-Operating_System
on	O
Linux	B-Application
,	O
Unix	B-Application
,	O
or	O
macOS	B-Application
.	O
</s>
<s>
Ca	B-Device
n't	I-Device
extend	I-Device
-	O
an	O
error	B-Error_Name
message	I-Error_Name
from	O
Acorn	B-Application
DFS	I-Application
.	O
</s>
<s>
DFS	B-Application
stores	O
files	O
in	O
non-fragmented	O
contiguous	O
disk	O
space	O
,	O
this	O
error	O
is	O
caused	O
when	O
trying	O
to	O
extend	O
an	O
open	O
random-access	O
file	B-Operating_System
into	O
space	O
that	O
is	O
already	O
occupied	O
by	O
another	O
file	B-Operating_System
.	O
</s>
<s>
Guru	B-Device
Meditation	I-Device
-	O
an	O
error	B-Error_Name
message	I-Error_Name
from	O
the	O
Amiga	B-Device
,	O
roughly	O
analogous	O
to	O
a	O
kernel	B-Operating_System
panic	I-Operating_System
or	O
BSOD	O
,	O
also	O
adopted	O
by	O
more	O
recent	O
products	O
such	O
as	O
VirtualBox	B-Operating_System
.	O
</s>
<s>
HTTP	B-Protocol
504	I-Protocol
-	O
An	O
error	O
found	O
on	O
the	O
World	O
Wide	O
Web	O
stating	O
that	O
a	O
gateway	O
timeout	O
occurred	O
in	O
the	O
internet	O
link	O
.	O
</s>
<s>
Error	O
1603	O
-	O
An	O
error	O
that	O
states	O
that	O
a	O
problem	O
during	O
installation	O
of	O
a	O
computer	B-Application
program	I-Application
,	O
this	O
error	O
particularly	O
occurs	O
on	O
Windows	O
computer	B-General_Concept
systems	O
.	O
</s>
<s>
application	O
name	O
has	O
stopped	O
-	O
An	O
error	B-Error_Name
message	I-Error_Name
commonly	O
found	O
on	O
Android	B-Application
devices	O
,	O
which	O
states	O
a	O
current	O
running	O
application	O
unexpectedly	O
stops	O
working	O
or	O
crashes	O
.	O
</s>
<s>
Success	O
-	O
one	O
of	O
the	O
error	B-Error_Name
messages	I-Error_Name
(	O
in	O
this	O
instance	O
,	O
POSIX	O
)	O
that	O
occurs	O
when	O
the	O
program	O
has	O
detected	O
an	O
error	O
condition	O
,	O
yet	O
the	O
actual	O
error	B-Error_Name
message	I-Error_Name
printing	O
routine	O
relies	O
on	O
C	B-Language
library	I-Language
to	O
print	O
the	O
error	O
reported	O
by	O
the	O
operating	B-General_Concept
system	I-General_Concept
(	O
in	O
this	O
case	O
,	O
errno.h	B-Error_Name
)	O
,	O
while	O
the	O
underlying	O
system	B-Operating_System
calls	I-Operating_System
have	O
succeeded	O
and	O
report	O
no	O
errors	O
(	O
in	O
this	O
case	O
,	O
errno	B-Error_Name
==	O
0	O
)	O
.	O
</s>
<s>
This	O
is	O
a	O
form	O
of	O
sloppy	O
error	B-General_Concept
handling	I-General_Concept
that	O
is	O
particularly	O
confusing	O
for	O
the	O
user	O
.	O
</s>
<s>
With	O
the	O
rise	O
of	O
Web	O
2.0	O
services	O
such	O
as	O
Twitter	B-Application
,	O
end-user	O
facing	O
error	B-Error_Name
messages	I-Error_Name
such	O
as	O
HTTP	B-Protocol
404	I-Protocol
and	O
HTTP	B-Protocol
500	I-Protocol
started	O
to	O
be	O
displayed	O
with	O
whimsical	O
characters	O
,	O
termed	O
Fail	O
Pets	O
or	O
Error	O
Mascots	O
.	O
</s>
<s>
Dr.	O
Sean	O
Rintel	O
argues	O
that	O
error	B-Error_Name
messages	I-Error_Name
are	O
a	O
critical	O
strategic	O
moment	O
in	O
brand	O
awareness	O
and	O
loyalty	O
.	O
</s>
<s>
The	O
most	O
famous	O
fail	O
pet	O
is	O
Twitter	B-Application
's	O
Fail	O
Whale	O
(	O
see	O
Twitter	B-Application
service	O
outages	O
)	O
.	O
</s>
<s>
FarmVille	B-Application
on	O
Facebook	O
:	O
Sad	O
cow	O
.	O
</s>
<s>
The	O
form	O
that	O
error	B-Error_Name
messages	I-Error_Name
take	O
varies	O
between	O
operating	B-General_Concept
systems	I-General_Concept
and	O
programs	O
.	O
</s>
<s>
Error	B-Error_Name
messages	I-Error_Name
on	O
hardware	B-Architecture
devices	O
,	O
like	O
computer	B-General_Concept
peripherals	O
,	O
may	O
take	O
the	O
form	O
of	O
dedicated	O
lights	O
indicating	O
an	O
error	O
condition	O
,	O
a	O
brief	O
code	O
that	O
needs	O
to	O
be	O
interpreted	O
using	O
a	O
look-up	O
sheet	O
or	O
a	O
manual	O
,	O
or	O
via	O
a	O
more	O
detailed	O
message	O
on	O
a	O
display	O
.	O
</s>
<s>
On	O
computers	O
,	O
error	B-Error_Name
messages	I-Error_Name
may	O
take	O
the	O
form	O
of	O
text	O
printed	O
to	O
a	O
console	O
,	O
or	O
they	O
may	O
be	O
presented	O
as	O
part	O
of	O
a	O
graphical	B-Application
user	I-Application
interface	I-Application
.	O
</s>
<s>
Error	B-Error_Name
messages	I-Error_Name
are	O
often	O
presented	O
as	O
a	O
dialog	O
box	O
,	O
which	O
makes	O
them	O
cause	O
a	O
following	O
mode	O
error	O
in	O
the	O
user	O
interaction	O
.	O
</s>
<s>
Instead	O
of	O
raising	O
an	O
error	B-Error_Name
message	I-Error_Name
the	O
system	O
design	O
should	O
have	O
avoided	O
the	O
conditions	O
that	O
caused	O
the	O
error	O
.	O
</s>
<s>
While	O
various	O
graphical	B-Application
user	I-Application
interfaces	I-Application
have	O
different	O
conventions	O
for	O
displaying	O
error	B-Error_Name
messages	I-Error_Name
,	O
several	O
techniques	O
have	O
become	O
common	O
:	O
</s>
<s>
A	O
dialog	O
box	O
,	O
or	O
pop-up	O
message	O
,	O
appears	O
in	O
a	O
window	O
on	O
the	O
screen	O
,	O
blocking	O
further	O
interaction	O
with	O
the	O
computer	B-General_Concept
until	O
it	O
is	O
acknowledged	O
.	O
</s>
<s>
On	O
Mac	B-Application
OS	I-Application
X	O
,	O
sheets	O
are	O
a	O
form	O
of	O
dialog	O
box	O
that	O
are	O
attached	O
to	O
a	O
specific	O
window	O
.	O
</s>
<s>
On	O
Mac	B-Application
OS	I-Application
X	O
,	O
notification	O
icons	O
may	O
appear	O
in	O
the	O
menu	O
bar	O
,	O
or	O
may	O
take	O
the	O
form	O
of	O
an	O
application	O
's	O
icon	O
"	O
bouncing	O
"	O
in	O
the	O
Dock	O
.	O
</s>
<s>
The	O
GNOME	B-Application
user	O
interface	O
for	O
Unix	B-Application
systems	I-Application
can	O
display	O
notification	O
icons	O
in	O
a	O
panel	O
.	O
</s>
<s>
The	O
three	O
main	O
factors	O
that	O
influence	O
the	O
design	B-Error_Name
of	I-Error_Name
error	I-Error_Name
messages	I-Error_Name
are	O
technical	O
limitations	O
,	O
the	O
amount	O
of	O
information	O
to	O
be	O
presented	O
,	O
and	O
what	O
kind	O
of	O
user	O
input	O
is	O
required	O
.	O
</s>
<s>
Some	O
systems	O
have	O
technical	O
limitations	O
that	O
may	O
constrain	O
the	O
amount	O
of	O
information	O
an	O
error	B-Error_Name
message	I-Error_Name
can	O
contain	O
.	O
</s>
<s>
For	O
example	O
,	O
a	O
printer	O
with	O
a	O
sixteen-character	O
alphanumeric	O
display	O
can	O
only	O
show	O
a	O
very	O
limited	O
amount	O
of	O
information	O
at	O
once	O
,	O
so	O
it	O
may	O
need	O
to	O
display	O
very	O
terse	O
error	B-Error_Name
messages	I-Error_Name
.	O
</s>
<s>
Even	O
with	O
computer	B-General_Concept
monitors	O
,	O
the	O
programmer	O
must	O
consider	O
the	O
smallest	O
monitor	O
that	O
a	O
user	O
might	O
reasonably	O
use	O
,	O
and	O
ensure	O
that	O
any	O
error	B-Error_Name
messages	I-Error_Name
will	O
fit	O
on	O
that	O
screen	O
.	O
</s>
<s>
The	O
nature	O
of	O
the	O
error	O
determines	O
the	O
amount	O
of	O
information	O
required	O
to	O
effectively	O
convey	O
the	O
error	B-Error_Name
message	I-Error_Name
.	O
</s>
<s>
A	O
complex	O
issue	O
may	O
require	O
a	O
more	O
detailed	O
error	B-Error_Name
message	I-Error_Name
in	O
order	O
to	O
adequately	O
inform	O
the	O
user	O
of	O
the	O
problem	O
.	O
</s>
<s>
When	O
designing	O
error	B-Error_Name
messages	I-Error_Name
,	O
software	O
designers	O
should	O
take	O
care	O
to	O
avoid	O
creating	O
security	O
vulnerabilities	O
.	O
</s>
<s>
Error	B-Error_Name
message	I-Error_Name
should	O
not	O
expose	O
information	O
that	O
can	O
be	O
exploited	O
by	O
a	O
cracker	B-Application
to	O
obtain	O
information	O
that	O
is	O
otherwise	O
difficult	O
to	O
obtain	O
.	O
</s>
<s>
Examples	O
are	O
systems	O
which	O
may	O
show	O
either	O
"	O
invalid	O
user	O
"	O
or	O
"	O
invalid	O
password	O
"	O
depending	O
on	O
which	O
is	O
incorrect	O
,	O
and	O
the	O
error	O
page	O
in	O
the	O
web	B-Application
server	I-Application
IIS	B-Application
5.0	I-Application
which	O
provides	O
a	O
complete	O
technical	O
description	O
of	O
the	O
error	O
including	O
a	O
source	O
code	O
fragment	O
.	O
</s>
