LykosAI/StabilityMatrix · error · InvalidOperationException

Expected network name.

Error message

Expected network name.

What it means

Thrown by ParseNetwork when the token following the ':' after the network type is missing or not scoped as 'meta.embedded.network.model.prompt'. The parser needs the model file name (without extension) at that position. Message reads 'Expected network name.'

Solutions

1. Provide the model name after the colon: '<lora:myModel:0.8>'
2. Use the model file name without the .safetensors/.ckpt extension, matching how the tokenizer scopes it
3. Ensure no double colons or empty name segments inside the tag
4. Catch InvalidOperationException to reject malformed network tags with a clear message

Example fix

// before
var prompt = "<lora::0.8>";
// after
var prompt = "<lora:myModel:0.8>";

bool HasModelName(string tag) => System.Text.RegularExpressions.Regex.IsMatch(tag, "^<[a-zA-Z]+:[^:<> ]+");

null

try { var node = builder.Parse(prompt); } catch (InvalidOperationException ex) when (ex.Message.Contains("network name")) { // report empty model name after ':' }

When it happens

Trigger: Input like '<lora:>' with an empty name, '<lora::1.0>' with a second colon but no name, or input ending after the first ':'.

Common situations: Templates with '<lora:NAME:0.7>' placeholders left unfilled; users deleting the model name when editing prompts; tags copied from tools where the name part got truncated.

Understand the failure class

Background: "missing required argument" and "the following required arguments were not provided": what required-argument errors mean and how to fix them — this error's family across 20 libraries.

Related errors

• Expected opening bracket.
• Expected network type.
• Expected colon.
• Expected network weight.
• Expected closing bracket.

AI-assisted analysis of LykosAI/StabilityMatrix@af93d6ef57 (2026-09-12). Data as JSON: /api/errors/8755a8115f433110. Report an issue: GitHub.

Appendix: source

Thrown at StabilityMatrix.Core/Models/PromptSyntax/PromptSyntaxBuilder.cs:257

            || !beginNetworkToken.Scopes.Contains("punctuation.definition.network.begin.prompt")
        )
            throw new InvalidOperationException("Expected opening bracket.");

        // type
        var typeToken = PeekToken();
        if (typeToken is null || !typeToken.Scopes.Contains("meta.embedded.network.type.prompt"))
            throw new InvalidOperationException("Expected network type.");
        var type = ParseIdentifier();

        // colon
        var colonToken = ConsumeToken();
        if (colonToken is null || !colonToken.Scopes.Contains("punctuation.separator.variable.prompt"))
            throw new InvalidOperationException("Expected colon.");

        // name
        var nameToken = PeekToken();
        if (nameToken is null || !nameToken.Scopes.Contains("meta.embedded.network.model.prompt"))
            throw new InvalidOperationException("Expected network name.");
        var name = ParseText();

        // model weight, clip weight
        NumberNode? modelWeight = null;
        NumberNode? clipWeight = null;

        // colon
        var nextToken = PeekToken();
        if (nextToken is not null && nextToken.Scopes.Contains("punctuation.separator.variable.prompt"))
        {
            ConsumeToken(); // consume colon

            // Parse the model weight.
            var modelWeightToken = ConsumeToken();
            if (modelWeightToken is null || !modelWeightToken.Scopes.Contains("constant.numeric"))
                throw new InvalidOperationException("Expected network weight.");
            modelWeight = ParseNumber();

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