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Event icon · error

This Error Event is part of Tweak App Events.

Event ID · 421400

"Tweak App failed on process"


The error message Tweak App failed indicates that the Tweak App Action failed to change CPU priority of an application, or CPU pinning was not successful.


The reasons for the failure can range from the specified program is not running (or just closed) to the provided Run As user credentials lacking the necessary privileges to modify running Windows processes.

Additionally, if you attempt to modify the CPU thread affinity on a machine that lacks the specified CPU cores, an error may arise. For instance, assigning an app to the 8th core when the machine only has 4 logical CPUs, may result in the Parameter is incorrect error being logged.

Event examples

See some examples of the Tweak App failed Event messages:

  • Task "Adjust Cores" Action "Tweak App" failed on "Custom Renderer". Access is denied. [os:5; aw:9]
  • Action "Tweak App" failed on "Chrome". The handle is invalid. [os:6; aw:21]
  • Failed on "3dsmax.exe". The system cannot find the file specified. [os:2; aw:7]
  • Failed on "7-zip". The parameter is incorrect. [os:87; aw:44]


Make sure that the specified application is running, that the provided path and name of the executable is spelled correctly, or the process identification (PID) exists.

Furthermore, make sure that your machine actually has the specific CPU cores or threads that you are trying to assign to a particular app. The CPU pinning fails if you try to allocate a non-existent core to an app or background process.

Syntax reminder

The Tweak App Action may encounter a "syntax" error when it is attempting to locate a process while no input is provided for the App name or executable.

If you are using dynamic variables, it is possible that the variable is empty. An example of the actual error message:

  • The filename, directory name, or volume label syntax is incorrect. [os:123; aw:36]

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