Discussion:
Unable to connect to (Legacy) UC controllers with Tracer TU over USB.
TU USB Driver evousb.sys (UC600) Blocked by Microsoft Driver Policy.
We have seen couple issues with Technician laptops and USB driver showing Error 43 or untrusted.
Symbio controllers use Windows Driver, doesn't have the issue.
UC210, UC400, UC600, UC800 controllers use a Trane Signed Driver, UC210 and UC400 are using the same driver.
We have seen an error 52 wen connecting to UC controllers.
Under device manager and Universal Serial Bus controllers, when connecting to Symbio devices you should see the Drivers like below.
Below is showing an issue with the Driver, when you highlight the driver and right click and enter Properties.
selecting the Driver
Accessing the properties for the Driver.
Issues:
In Device Manager, details for error code 43 are available when you view a device's status in its
properties which are displayed as below:
Windows has stopped this device because it has reported problems (code 43)."
This error occurs if the device hardware fails or the device driver fails. Most of the code 43
errors appear on video cards and USB devices like printers, webcams, and related peripherals.
UC400 Driver had a similar issue; we have seen error Code 52.
Error indicating Windows cannot verify the digital signature for the UC400 USB driver.
This error can occur due to several reasons, including corrupted drivers, incorrect or unverified digital signatures, or restrictions imposed by the Secure Boot of the BIOS. To resolve this issue, you can try the following steps:
How to Fix USB Error Digital Signature (Code 52) Error
UC400 Driver Had the following error Code 39; this is also related to User Permissions on the computer.
Windows cannot load the device driver for this hardware. The driver may be corrupted or missing. (Code 39)
Error 39, Windows cannot load device driver; Corrupted or missing
evousb.sys error message; does not pass the Windows driver policy.
Work Around:
Disable the Microsoft Vulnerable Driver Blocklist, if managed by IT you may need to get help from them to disable the security feature.
evousb.sys error we are getting looks like it is solved by going to Windows>Settings>Privacy and Security>Windows Security>Device Security>Core Isolation Details and turn off Microsoft Vulnerable Driver Blocklist
Notes:
DDJ 6/12/2026 - Development team has a plan to sign the driver and deliver a solution to customers having this issue.
Issues are related to the Microsoft Security updates for April 2026 for Windows 11.