Here is a question related to the solution with the error you described:

What steps can be taken to resolve the M134-Failed to take photos of materials on the right tray three times in a row error condition on a KM-ASSYM5-02 machine with error id 6
The M134 error occurs when the machine is unable to take photos of materials on the right tray three times in a row. To solve this error, you can check if the tray is in the correct position and if there are any obstructions