Enum describing possible experiment arm errors.

[Proto definition ![GitHub](https://developers.google.com/site-assets/logo-github.svg)](https://github.com/googleapis/googleapis/blob/master/google/ads/googleads/v26/errors/experiment_arm_error.proto)

| Enums ||
|---|---|
| ## `ADOPT_AI_MAX_CAMPAIGN_ALREADY_ENABLED` | Campaign already has AI Max enabled and can't participate in ADOPT_AI_MAX experiment. |
| ## `ADOPT_AI_MAX_CAMPAIGN_MISSING_PERFORMANCE_SEARCH_ENABLED` | Campaign must enable performance search setting for ADOPT_AI_MAX experiments. |
| ## `BIDDING_STRATEGY_NOT_SUPPORTED_IN_EXPERIMENTS` | Bidding strategy is not supported in experiments. |
| ## `BUDGET_MUST_NOT_BE_SHARED` | Shared budgets are not allowed in experiments. |
| ## `CANNOT_ADD_BASE_CAMPAIGN_WITH_DATE_RANGE` | Experiment date range must be within base campaign's date range. |
| ## `CANNOT_ADD_CAMPAIGNS_WITH_DYNAMIC_ASSETS_ENABLED` | Cannot have enable_dynamic_assets turned on in experiment's campaigns. |
| ## `CANNOT_ADD_CAMPAIGN_WITH_CUSTOM_BUDGET` | Cannot use custom budget on experiment's control campaigns. |
| ## `CANNOT_ADD_CAMPAIGN_WITH_SHARED_BUDGET` | Cannot use shared budget on experiment's control campaign. |
| ## `CANNOT_ADD_CAMPAIGN_WITH_TARGET_ROAS_TOLERANCE_PERCENT_MILLIS` | AI Max experiments do not support campaigns with a target ROAS tolerance (see campaign.maximize_conversion_value.target_roas_tolerance_percent_millis). |
| ## `CANNOT_HAVE_SAME_CAMPAIGN_CROSS_ARMS_IN_ONE_EXPERIMENT` | A campaign cannot be added to multiple arms in one experiment. Use different campaigns in each arm of the experiment. |
| ## `CANNOT_MODIFY_CAMPAIGN_IDS` | Cannot edit campaign ids in trial arms in non SETUP experiment. |
| ## `CANNOT_MODIFY_CAMPAIGN_WITHOUT_SUFFIX_SET` | Cannot modify the campaigns in the control arm if there is not a suffix set in the trial. |
| ## `CANNOT_MUTATE_TRAFFIC_SPLIT_AFTER_START` | Traffic split related settings (like traffic share bounds) can't be modified after the trial has started. |
| ## `CANNOT_SET_TREATMENT_ARM_CAMPAIGN` | Cannot set campaigns of treatment experiment arm. |
| ## `DUPLICATE_ASSET_GROUP_ASSETS_BETWEEN_ARMS` | An asset group asset cannot be added to multiple arms in one experiment. Use different asset group assets in each arm of the experiment. |
| ## `DUPLICATE_ASSET_GROUP_ASSETS_IN_ONE_ARM` | An asset group asset cannot be used multiple times in one arm. Use different asset group assets in one arm of the experiment. |
| ## `DUPLICATE_EXPERIMENT_ARM_NAME` | Cannot add duplicate experiment arm name in one experiment. |
| ## `EXPERIMENT_ARM_COUNT_LIMIT_EXCEEDED` | Number of experiment arms is above limit. |
| ## `INVALID_CAMPAIGN_STATUS` | Cannot add campaign with invalid status to the experiment arm. |
| ## `SEARCH_PLUS_CAMPAIGN_NOT_ALLOWED` | Campaigns in the ADOPT_BROAD_MATCH_KEYWORD experiment cannot target the Google Display Network. |
| ## `TOO_MANY_CAMPAIGNS_IN_EXPERIMENT_ARM` | Number of campaigns in the experiment arm is above limit. |
| ## `TRAFFIC_SPLIT_NOT_SUPPORTED_FOR_CHANNEL_TYPE` | Traffic split is not supported for some channel types. |
| ## `UNKNOWN` | The received error code is not known in this version. |
| ## `UNSPECIFIED` | Enum unspecified. |
| ## `UNSUPPORTED_CAMPAIGN_ADVERTISING_CHANNEL_SUB_TYPE` | Cannot use campaign's advertising channel sub type in experiment. |