Revenue Cloud: Initiate Renewal action in flow fails with '<recordId> : null' error and no renewal quote is created

Follow the causes in order. Each cause ends with a verification step.

Cause 1: Running user is missing the InitiateRenewal API permission set
1. Navigate to Setup > Users > Process Automation Settings and note the Default Workflow User. Scheduled and platform-event flow templates (including Automatically Renew Expiring Assets) execute as this user.
2. Navigate to Setup > Permission Sets > InitiateRenewal API.
3. Click Manage Assignments > Add Assignment, select the Default Workflow User and any user running the flow in debug, and click Assign.
4. Confirm the issue is resolved by re-running the flow in Setup > Flows > [Your Flow] > Debug against a previously failing Order and verifying the renewal quote is created on the Renewal Opportunity.

Cause 2: Renewable assets are missing Renewal Term or Renewal Term Unit
1. Open the failing Flow Interview in Setup > Paused and Failed Flow Interviews and copy the asset Id shown before " : null".
2. Open the Asset [Asset] record and confirm the fields Renewal Term [RenewalTerm] and Renewal Term Unit [RenewalTermUnit] are populated. The Initiate Renewal action returns "We couldn't renew the assets. All assets in a request must have values for RenewalTermUnit and RenewalTerm" when either field is null.
3. Populate Renewal Term [RenewalTerm] (numeric) and Renewal Term Unit [RenewalTermUnit] (Months or Years) on every renewable asset returned by the Get Renewable Assets Summary action.
4. To prevent recurrence, navigate to Setup > Object Manager > Contract > Page Layouts and add Renewal Term and Renewal Term Unit fields, then set them on the Contract before activating the order so they propagate to assets per the Create and Update Renewal Opportunities flow template prerequisites.
5. Confirm the issue is resolved by re-running the flow and verifying a renewal quote is generated under the renewal opportunity.

Cause 3: Auto-renewal fields are not exposed on the source records
1. Navigate to Setup > Object Manager > Product Selling Model > Page Layouts and add Automatically Renew Asset by Default [AutoRenewalDefault] to the layout.
2. Navigate to Setup > Object Manager > Quote Line Item, Order Item, and Asset, and add Automatically Renew [AutoRenew] to each layout.
3. On every asset that must auto-renew, set Automatically Renew [AutoRenew] to true.
4. Confirm the issue is resolved by running the Automatically Renew Expiring Assets flow in debug for an asset whose end date is within the value of the NumberOfDaysInTheFuture flow variable and verifying a renewal order is created and activated.

Cause 4: Known Issue — duplicate asset-parent bundle from a previous renewal (KI-08120)
1. Open the failing asset and navigate to its Asset Actions related list.
2. If a previous renewal quote contains a second instance of the same asset-parent bundle, this matches Known Issue KI-08120. There is no published workaround; remove the duplicate bundle line from the prior renewal quote and re-run the renewal.
3. Confirm the issue is resolved by re-running the flow against the corrected asset.

Cause 5: Known Issue — overlapping contract durations on Asset Contract Relationship (KI-70560)
1. Query the original Contract's Asset Contract Relationship [AssetContractRelationship] records.
2. Per KI-70560, clear the End Date [EndDate] on the original contract's ACR record where it overlaps the new renewal contract.
3. Re-run the flow.
4. Confirm the issue is resolved by verifying ACR records generate on the renewal contract without the error "Asset can't be associated with multiple Contracts with overlapping date durations".

Cause 6: Known Issue — UOM populated at product level causes decimal-quantity failure (KI-65555)
1. If renewable assets reference a Product2 with a Unit of Measure [QuantityUnitOfMeasure] populated and decimal quantities at quote level, this matches KI-65555. No workaround is currently published; track the Known Issue for resolution.

Cause 7: Scheduled flow heap limit (KI-70257)
1. If the failure occurs only in scheduled runs and Paused and Failed Flow Interviews shows no error text, navigate to Setup > Flows > [Your Flow] > Debug and run the flow against a single record matching its entry criteria. Per KI-70257, heap-limit exceptions surface in the debugger but not in failed interviews.
2. If a heap exception appears, reduce the volume of records aggregated per interview by tightening the flow's entry criteria or processing renewable assets in smaller batches.
3. Confirm the issue is resolved by re-running the scheduled flow and verifying it completes without entering Paused and Failed Flow Interviews.