This is an error that is not recognized by your Ultimaker S-line printer. It can occur when there is a mismatch between the installed electronics and firmware. In this case, it seems there is a problem with the printer control software.
This can usually be easily resolved by following these steps:
- Power cycle the Ultimaker S3/S5 using the on/off switch. Wait until the printer has completely shut down before turning it on again
- Update the firmware to the latest stable version
If the problem still persists, please contact support by raising a support request above.
Note: This error was formerly known as ER27.