Italian Fiscal Printer Commands Failing in Mews Connector (Windows)

Incident Report for Mews

Postmortem

Problem

On Tue, 01 Sep 2026 11:59:00 UTC, a new version of the Mews Connector (v1.1.183) introduced an issue that prevented receipt printing on Italian fiscal printers. Properties using these printers saw their fiscal device commands enter an error state, meaning receipts could not be reported to the fiscal printer.

Action

Our team detected the issue within minutes of the first errors appearing and immediately began investigating. We initially attempted to restore the previous working version, but further testing revealed the issue required a targeted fix rather than a rollback. A corrected version (v1.1.185) was built, tested, and released on Tue, 01 Sep 2026 15:38:00 UTC. The update rolled out automatically to connected Connector instances and was also made available for manual download. By Tue, 01 Sep 2026 17:24:29 UTC, the fix had reached over 95% of instances and the issue was confirmed resolved. Properties were advised to retry any device commands that had entered an error state once the update was installed.

Causes

A software dependency used by the Connector's fiscal printer module was resolved incorrectly during the build process, resulting in a version mismatch that caused the application to fail when attempting to communicate with Italian fiscal printers. This was a build-environment issue rather than a deliberate code change, which is why rebuilding the previous version's code did not resolve the problem.

Solutions

  • Released Mews Connector v1.1.185, which resolved the dependency mismatch and restored normal fiscal printer operation.
  • Affected device commands could be retried after the update was installed — no data was lost.
  • We are pinning all software dependencies to specific versions to prevent build-environment drift from causing similar issues in the future.
  • We are adding additional pre-release validation steps that specifically test fiscal printer functionality before new Mews Connector versions are released.
  • In Q4 2026 we will replace the current on-premise Italian fiscal printer integration with a cloud-based Italian fiscal integration, removing this class of dependency issue for Italian properties.
Posted Sep 10, 2026 - 14:47 CEST

Resolved

Version 1.1.185 of the Mews Connector solved the issue.
If you are on Mews Connector version 1.1.183 or 1.1.184 please update to 1.1.185.
Once updated please retry the printer device commands.
Posted Sep 01, 2026 - 19:14 CEST

Update

Mews Connector version 1.1.185, which includes the fix, is being rolled out automatically. It can also be downloaded and installed manually.

https://store.mews.li/Package/Connector/InstallMewsConnector/Data

After updating, properties can retry any Italian fiscal printer device commands that are in an Error state.
Posted Sep 01, 2026 - 18:26 CEST

Monitoring

We identified an issue in Mews Connector versions 1.1.183 and 1.1.184 that caused device commands sent to Italian fiscal printers to fail. A fix is currently being released in Mews Connector version 1.1.185.

Apologies for the inconvenience.
Posted Sep 01, 2026 - 17:38 CEST
This incident affected: Mews Operations.