# How to Troubleshoot Version Catalog Problems in Gradle

version 9.6.0-20260609061938+0000

Version catalogs help manage dependencies efficiently, but sometimes errors occur.

This guide provides quick solutions to common version catalog issues in Gradle.

## 1. Fixing Accessor Name Clashes

Error: Two aliases in your version catalog map to the same accessor.

    someAlias = { module="org.sample:lib", version="1.0" }
    some-alias = { module="org.sample:other-lib", version="2.0" }

Solution: Choose distinct alias names to avoid conflicts.

    firstAlias = { module="org.sample:lib", version="1.0" }
    secondAlias = { module="org.sample:other-lib", version="2.0" }

## 2. Handling Too Many Entries in a Catalog

Error: The catalog exceeds the 32,000 entry limit imposed by the JVM file format.

Solution: Split your catalog into multiple smaller catalogs.

## 3. Resolving Reserved Alias Names

Error: An alias uses a reserved name like `versions`, `bundles`, `plugins`, `extensions`, or `class`.

    versions = { module="org.sample:lib", version="1.0" }

Solution: Choose a different alias name.

    sampleLib = { module="org.sample:lib", version="1.0" }

## 4. Fixing Undefined Version References

Error: A library references a non-existent version in the catalog.

    [libraries]
    myLib = { module="org.sample:lib", version.ref="undefinedVersion" }

Solution: Either correct the reference or declare the missing version in the catalog.

    [versions]
    definedVersion = "1.0"

    [libraries]
    myLib = { module="org.sample:lib", version.ref="definedVersion" }

## 5. Fixing Undefined Alias References

Error: A bundle references a library that does not exist in the catalog.

    [bundles]
    myBundle = ["existingLib", "undefinedLib"]

Solution: Ensure the library is defined in the catalog or remove it from the bundle.

    [bundles]
    myBundle = ["existingLib"]

## 6. Correcting Invalid Dependency Notation

Error: An alias has an incorrect dependency notation.

Solution: Use the correct syntax:

    library("some-alias", "com.mycompany:some-lib:1.1").withoutVersion()

    [libraries]
    some-alias = { module="com.mycompany:some-lib", version="1.1" }

## 7. Fixing Unsupported Catalog File Formats

Error: An invalid catalog file format (e.g., `.txt`) was used.

Solution: Use a TOML file or the `Settings` API.

## 8. Handling Missing Catalog Files

Error: The specified catalog file does not exist.

Solution: Ensure the file exists before attempting to import it.

## 9. Correcting Invalid Alias or Bundle Notation

Error: The alias name does not match the required format (`[a-z]([a-zA-Z0-9_.\-])`).

    Alias! = { module="org.sample:lib", version="1.0" }

Solution: Use a valid alias name such as `some-alias`.

    valid-alias = { module="org.sample:lib", version="1.0" }

## 10. Fixing Invalid Module Notation in TOML

Error: Incorrect `module` notation in the version catalog.

Solution: Use the correct format:

    [libraries]
    groovy = { module="org.codehaus.groovy:groovy", version="3.0.5" }

## 11. Resolving Invalid TOML Syntax

Error: Syntax or grammar issues in the TOML file.

Solution: Ensure correct keys and structure:

    some-alias = { group="my-lib", name="1.0" }

## 12. Handling Unsupported TOML File Versions

Error: The catalog file uses a version unsupported by your Gradle installation.

Solution: Upgrade Gradle to a newer version.

## 13. Fixing Invalid Plugin Notation

Error: The plugin alias notation does not separate the plugin ID from the version.

Solution: Use the correct format: `plugin.id:version`.

    [plugins]
    spring-boot = { id="org.springframework.boot", version="2.5.2" }

## 14. Resolving Unfinished Aliases

Error: An alias was created but not registered in the catalog.

Solution: Call `.version()` or `.withoutVersion()` to complete the alias.

    library("some-alias", "org.sample:lib").version("1.0")

## 15. Fixing Multiple Import Invocations

Error: An import statement was called more than once.

Solution: Ensure each version catalog has a single import invocation.

## 16. Handling Missing Import Files

Error: The import statement references a file that does not exist.

Solution: Ensure the specified file is available before import.

## 17. Fixing Too Many Import Files

Error: The import statement references multiple files.

Solution: Ensure only a single file is specified for import.

## 18. Resolving Invalid TOML Definitions

Error: A TOML table contains a key that is not allowed at that location (e.g. an unknown attribute on a library or version declaration).

Solution: Remove the unexpected key, or use one of the keys allowed by the surrounding table (such as `group`, `module`, `name`, `version` for a library declaration).

## 19. Correcting Invalid Version Notation

Error: A version string uses syntax that cannot be parsed (for example, the strict version modifier `!!` was placed without a base version before it).

Solution: Place a valid version number before the `!!` modifier, e.g. `1.0!!`, or remove the modifier when it is not needed.