Enum describing possible experiment 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_error.proto)

| Enums ||
|---|---|
| ## `CANNOT_ADD_CAMPAIGN_WITH_DEPRECATED_AD_TYPES` | Cannot add campaign with deprecated ad types. Deprecated ad types: ENHANCED_DISPLAY, GALLERY, GMAIL, KEYWORDLESS, TEXT. |
| ## `CANNOT_CREATE_EXPERIMENT_CAMPAIGN_WITH_CUSTOM_BUDGET` | Cannot use custom budget on base campaign when scheduling an experiment. |
| ## `CANNOT_CREATE_EXPERIMENT_CAMPAIGN_WITH_SHARED_BUDGET` | Cannot use shared budget on base campaign when scheduling an experiment. |
| ## `CANNOT_ENABLE_SYNC_FOR_UNSUPPORTED_EXPERIMENT_TYPE` | Sync can only be enabled for supported experiment types. Supported experiment types: SEARCH_CUSTOM, DISPLAY_CUSTOM, DISPLAY_AUTOMATED_BIDDING_STRATEGY, SEARCH_AUTOMATED_BIDDING_STRATEGY. |
| ## `CANNOT_HAVE_MULTIPLE_CONTROL_ARMS` | The experiment cannot have more than one control arm. |
| ## `CANNOT_MODIFY_PAST_END_DATE` | The end date of an expired experiment cannot be modified. |
| ## `CANNOT_MODIFY_REMOVED_EXPERIMENT` | Experiments can only be modified when they are ENABLED. |
| ## `CANNOT_MODIFY_TRAFFIC_SPLIT_AFTER_START` | Traffic split related settings (like traffic share bounds) can't be modified after the experiment has started. |
| ## `CANNOT_REMOVE_IN_CREATION_EXPERIMENT` | Cannot remove in creation experiments. |
| ## `CANNOT_SET_END_DATE_IN_PAST` | The end date of an experiment cannot be set in the past. |
| ## `CANNOT_SET_START_DATE_IN_PAST` | The start date of an experiment cannot be set in the past. Use a start date in the future. |
| ## `CANNOT_SET_STATUS_TO_GRADUATED` | Clients must use the graduate action to graduate experiments and cannot set the status to GRADUATED directly. |
| ## `CANNOT_SET_STATUS_TO_REMOVED` | The status of an experiment cannot be set to REMOVED. |
| ## `DUPLICATE_EXPERIMENT_CAMPAIGN_NAME` | The experiment campaign name conflicts with a pre-existing campaign. |
| ## `DUPLICATE_EXPERIMENT_NAME` | The experiment has the same name as an existing active experiment. |
| ## `END_DATE_BEFORE_START_DATE` | The end date of an experiment is before its start date. Use an end date after the start date. |
| ## `EXPERIMENT_NOT_FOUND` | The experiment could not be found. |
| ## `EXPERIMENT_NOT_YET_STARTED` | Experiment has not begun. |
| ## `INVALID_CAMPAIGN_CHANNEL_TYPE` | Experiment arm contains campaigns with invalid advertising channel type. |
| ## `INVALID_DURATION_FOR_AN_EXPERIMENT` | Experiment length cannot be longer than max length. |
| ## `INVALID_STATUS` | The status is invalid. |
| ## `INVALID_TRIAL_ARM_TRAFFIC_SPLIT` | Experiment arm contains invalid traffic split. |
| ## `IN_DESIGN_CAMPAIGNS_NOT_SET` | The experiment doesn't set in-design campaigns. |
| ## `MISSING_EU_POLITICAL_ADVERTISING_SELF_DECLARATION` | The experiment's campaigns must self-declare whether they contain political advertising that targets the European Union. |
| ## `MISSING_EXPERIMENT_ARMS` | Cannot create an experiment with no arms. |
| ## `MISSING_VIDEO_EXPERIMENT_SUBTYPE` | The video experiment subtype is missing. |
| ## `OVERLAPPING_MEMBERS_AND_DATE_RANGE` | A pair of trials share members and have overlapping date ranges. |
| ## `START_DATE_ALREADY_PASSED` | The start date of an experiment cannot be modified if the existing start date has already passed. |
| ## `START_DATE_TOO_FAR_IN_FUTURE` | The start date of an experiment is too far in the future. Use a start date no more than 1 year in the future. |
| ## `STATUS_TRANSITION_INVALID` | Invalid status transition. |
| ## `SUM_TRIAL_ARM_TRAFFIC_UNEQUALS_TO_TRIAL_TRAFFIC_SPLIT_DENOMINATOR` | The total traffic split of trial arms is not equal to 100. |
| ## `TRAFFIC_SPLIT_OVERLAPPING` | Experiment contains trial arms with overlapping traffic split. |
| ## `UNKNOWN` | The received error code is not known in this version. |
| ## `UNSPECIFIED` | Enum unspecified. |