MATLAB: Do I get a “Cannot find a license for Fixed_Point_Toolbox” error when I’m not even using it the Simulink model

booleanconversionfixptmultiplicationsimulinktype

I'm running Simulink for my team's BEST Robotics competition and I'm having issues with the R2018b version of MATLAB. When I went to Build, Deploy and Start, and it popped up with a message that said I did not have the correct license. Here's the error message:
=== Build (Elapsed: 3 sec) ===
    ### Starting build procedure for model: Colton2
    ### Generating code and artifacts to 'Model specific' folder structure
    ### Generating code into build folder: C:\Users\tschroeder\Desktop\Programming\2019 Programming\Colton\Colton2_ert_rtw
    ### Build procedure for model: 'Colton2' aborted due to an error.
    Error:License checkout failed.
    License Manager Error -5
    Cannot find a license for Fixed_Point_Toolbox.
      Troubleshoot this issue by visiting: 
      https://www.mathworks.com/support/lme/R2019b/5
      Diagnostic Information:
      Feature: Fixed_Point_Toolbox 
      License path: C:\Users\tschroeder\AppData\Roaming\MathWorks\MATLAB\R2019b_licenses;C:\Program Files\MATLAB\R2019b\licenses\license.dat;C:\Program   Files\MATLAB\R2019b\licenses\license_tmcdougal-desktop_40779792_R2019b.lic 
      Licensing error: -5,357.

Best Answer

This error occurs when you perform a math operation such as a multiplication to a signal of type boolean. An easy way to check if Simulink is propagating signals that can cause this error is by displaying the port data types.
In version R2019a and prior, you can do this by by navigating to - Display > Signals & Ports > Port Data Types
For R2019b and later, click on the 'Debug' tab > Expand 'Information Overlays' dropdown > Scroll down to 'Ports' and select 'Base Data Types'
Once the port types are visible, check for any data type that has the word "fix". To solve the issue, simply use a "Data Type Conversion" block to convert the boolean signal to something like a double before connecting any other block.
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