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 😃

Sources

This page was built from the findings of many.

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