PNG ICO ICNS MORE
Air
wrong, exclamation, warning
Firebrick
128x128
Refresh CL
wrong, Alert, warning
256x256
iCandy Junior
Error, warning, Alert
PNG ICO MORE
Network & communications
Photorealistic
Network
safety, shield, Error
512x512
Signs & symbols
Glyph
Buttons
Error, Lock, Clear
Pixel
16x16 Free Application Icons
prohibition, danger, reject
16x16
Mixed
3D
Momentum Glossy icons
Books, Error
32x32
PNG MORE
Koloria icons pack
base, Error, utilize
21x21
base, Error, formula1
30x30
UI
Handdrawn
Hand Drawn Web Icon Set
Error, date
Error, Favourite
Business & finance
Error
Files & folders
Smooth
Spirit20
system, 02, Error
20x20
Gnome Web Icons
Gnome, Dialog, Error
48x48
64, Gnome, Dialog
64x64
Gnome icons
cancel, Error, gtk
Desktop apps
One bit
false, remove, Error
Error, Exit, remove
Led Icons
Error, cross, Exit
Computer & hardware
realistiK Reloaded
x, cancel, Error