| Message | Cause | Fix |
|---|
| Artifact is unreachable / cannot be resolved | Reference to a deleted item or to a toolkit dependency that was removed / re-added (new dependency id) | Re-select the item in the referencing artifact, or revert to the snapshot before the dependency change (question 3145) |
| Variable X is not defined / type not found | Business object deleted or renamed; toolkit snapshot changed the BO | Re-select the type in the variables tab; upgrade the dependency |
| Data mapping refers to a variable that does not exist | Service's input / output renamed after the mapping was made | Open the activity's Data Mapping and re-map |
| Coach view configuration option is missing / of the wrong type | Custom view's options changed after use | Reopen the coach, delete and re-add the affected values |
| Team / participant not found | Team deleted or the app's default team changed | Assign a team on the activity / BPD exposure |
| Sequence flow without condition / activity without outgoing flow | Modelling error | Add the default flow / connect the node |
| Deprecated artifact (heritage coach, old control) | Warning only | Convert when convenient; blocks nothing except on CP4BA |
| External service / Server definition not found | Server definition deleted or renamed | Recreate the Server in Process App Settings and re-select it in the integration |
| Duplicate name in the same folder / invalid characters | Rename conflicts after copy | Rename |
| Toolkit dependency in a snapshot that is archived / not installed | Installing an app whose toolkit snapshot is missing on the server | Install the toolkit snapshot first (online servers do it automatically) |