Waaa087 Fixed

When the software reports that a variable is it does not merely mean "it cannot be changed." It means the variable has been assigned a specific memory attribute that prohibits runtime modification via the standard Watch Window interface.

When CX-Programmer compiles a program with AT assignments, it treats these memory locations as hardware-bound. If the variable is an Input ( %I ) or Output ( %Q ), the PLC operating system "locks" these addresses because they are refreshed by the I/O bus scan. Attempting to force a value into a "Fixed" memory address that is being actively updated by hardware creates a race condition. waaa087 fixed

Internal tracking showed the error occurred most frequently on nodes running scheduler version 4.2.1 with persistent connection pooling enabled. Affected requests returned an unhandled exception leading to a partial stack trace referencing handler/session.py:442 . When the software reports that a variable is