cfx example to solve the problem

This answer quotes ChatGPT
This error indicates that the diffusion coefficient of the variable TKE_FL1 was set incorrectly in the calculation, resulting in an error in solving the equation TKE_FL.

To solve this problem, it is recommended that you follow these steps:

Check that the diffusion coefficient of the TKE_FL1 variable in the input file or model Settings is correct, either by looking at the appropriate documentation or by asking the model developer for help.

Verify that the entered values meet the requirements, such as whether the diffusion coefficient is outside the allowed range.

If the problem still cannot be solved, consider using other diffusion coefficients or try modifying the model Settings or boundary conditions.

Are you setting unreasonable model parameters or model boundary conditions, I estimate that I am trying to get the difffusion coefficient out of my computer.