# Common Errors

This is a searchable list of error messages, and common fixes.

For a general guide to fixing code problems, see Debugging

# Error <instance id> (<object>) does not have variable '<variable name>'

  • Maybe you misspelled the variable name
  • Maybe the variable wasn't created yet
  • If you're using with to run code on a group of objects, maybe you're affecting more than you mean to, and need an if.
  • If the error is in draw_hud.gml, it's because draw_hud.gml runs once before init.gml, giving a single error.
    To avoid the error, try setting initialized = true (named whatever) in init.gml and if not 'initialized' in self { exit } at the top of draw_hud.gml. That will skip draw_hud.gml if init.gml hasn't run yet.
  • If the missing variable is url, note that url only automatically exists on finished characters that have been uploaded to the workshop.

# Error Expected a statement, got <character>

There's probably an incomplete line that isn't a statement (a piece of code that does something).

For example, a line containing only attack == AT_DTILT doesn't do anything. == compares attack and AT_DTILT, and makes a true or false value, but that value isn't saved or used by anything.

# Error Type check failure for argument <argument num>: Expected a <correct type>

You're using the wrong type as one of the arguments, like a "3" text string when you need a 3 number.
See data types.

# Error unable to convert string ".png" to number

You may have named a spritesheet ending in _strip with no number at the end. Sprites should look like idle_strip4.png.

# Error Couldn't find instance <instance id>

There is probably code running referencing a destroyed article. Referencing a dead player may cause this?

See destroying articles safely.

# Error Connection error, there was a desync.

Desyncs are a notoriously tricky bug to fix. They occur in online games when two players have different game states.

When a desync occurs, screenshots are automatically logged to %localappdata%/RivalsofAether/desyncs

Things that can cause desyncs include:

  • Setting a non-local variable in draw scripts.
    Any variables set should be made local with var.
    This includes purely visual variables like colors and sprite indices.
  • GML's random functions, eg random_range. These will give different numbers for different players.
    Use random_func() and random_func_2()
  • GML's camera functions view_get_xview and view_get_yview.
    Try get_instance_x(asset_get("camera_obj")) instead.
  • Code based on the alt you have loaded.
    If both players load the same alt, the opponent's alt will automatically change, causing different states.
  • Anything that pauses the game, like get_string()
  • (Unconfirmed) Rounding numbers might sometimes cause desyncs. You can use floor instead if you're concerned.
  • (Unconfirmed) Articles with image_angle being not 0 might sometimes cause desyncs.

Assistant will automatically warn for some cases where it's able to detect desync prone code.

# Error cannot guarantee array type

This can occur if you try to alter an array from a subscript like my_array[0] = 5.

When changing a value in an array, use @ syntax. my_array[@ 0] = 0.

Other data types have other accessor syntax.

# Error add_compatiable_urls is not a valid function

The manual repeatedly misspells add_compatible_urls as add_compatiable_urls.

# Hitbox not Hitting

  • Is priority unset for the hitbox? Hitboxes with priority of 0 will not hit.
  • Try setting hitbox group to -1.

# Single Frame Attack Code Happening Every Frame During Hitpause

Special attack code often uses a frame check like window_timer == 1 or window_timer % 4 == 0 to make the code run on that particular frame.

However, during hitpause, the window_timer doesn't advance, which can cause the code to run each frame while the hitpause is active.

If using the assistant, consider using window_time_is(frame) instead of window_timer == frame to automatically check for hitpause.
Otherwise add and not hitpause to the check.

# set_attack Crashes in set_attack.gml

Calling set_attack in set_attack.gml risks creating an infinite loop.

Just write attack = when needed in set_attack.gml.

# Sprite is Floating or Clipping through the Stage

The sprite may not have been given the correct position in load.gml.

# Hud Sprite is in the Wrong Place

  • Referencing x or y
    temp_x and temp_y refer to the hud's base location.
  • Draw at raw coordinates like draw_sprite(..., ..., 100, 100) isn't wrong, but is often not what the programmer intended.
    Try temp_x+100, temp_y+100 instead.

# Strange Behavior When Breaking Kragg's Rock

If you have an AT_NSPECIAL projectile, when you break Kragg's rock, the fragments will count as being your AT_NSPECIAL projectiles.

This will trigger all of your character's scripts related to hitboxes, including got_parried.gml , hitbox_update.gml, and hit_player.gml.

The fragments store your character as being the original character, making it difficult to check for.

One work-around is to use a hit_priority not equal to 1, since Kragg's rock shards have a hit_priority of 1.
You can then check if (my_hitboxID.hit_priority != 1) inside any hitbox scripts, to see if it's really yours.

# Some Code is not Running

  • An error earlier in the script will immediately exit the script.
  • If the code is in an if or for block, the block may not be being entered. Debug the conditions before the block.

# White X Sprite / Error sound

The sprite requested by sprite_get or sound requested by sound_get was not found.

  • Is the file present and name correct?
  • The file type should not be included. Correct format is like sprite_get("dash") or sound_Get("air_horn").
  • These functions work on whatever is currently self, so they may misbehave inside a with block.

Under Construction

I'd like this page to be heavily expanded. Please contribute to my contact in the footer 😃


This page was built from the findings of many.

I was directly helped by: Frtoud, Mawral, Mr Nart, Supersonic