vertcat errors - need a 'workaround' solution

Please suggest a 'workaround' or alternate solution for the following error (code and data tables attached)

"An error occurred when concatenating the table variable 'ImpactWind' using VERTCAT. Caused by: Error using categorical/vertcat Ordinal arrays must have the same categories, including their order."

Note: categories are: 'other', 'airport', 'road', 'railway', 'bus-sta' ... and the common categories to both tables to vertcat are: 'other', 'airport', 'road'

load 'datatables.mat'; % note: two tables will load, C1 and R1, both have 'ImpactWind' as a variable column
X = vertcat(C1, R1)

Error using tabular/vertcat
An error occurred when concatenating the table variable 'ImpactWind' using VERTCAT.

Caused by:
Error using categorical/vertcat
Ordinal arrays must have the same categories, including their order.

Answer 1

[Stephen23]

S = load('datatables.mat')

S = struct with fields:
    C1: [3420×21 table]
    R1: [1025×21 table]

T1 = S.C1;
T2 = S.R1;
C1 = categories(T1.ImpactWind)

C1 = 4×1 cell array
    {'other'  }
    {'railway'}
    {'airport'}
    {'road'   }

C2 = categories(T2.ImpactWind)

C2 = 4×1 cell array
    {'other'  }
    {'airport'}
    {'road'   }
    {'bus-sta'}

C0 = unique([C1;C2],'stable')

C0 = 5×1 cell array
    {'other'  }
    {'railway'}
    {'airport'}
    {'road'   }
    {'bus-sta'}

T1.ImpactWind = setcats(T1.ImpactWind,C0);
T2.ImpactWind = setcats(T2.ImpactWind,C0);
T0 = [T1;T2]

T0 = 4445×21 table
    LAeq      VLFN      LFN       MFN       HFN       Day     Season    DayNumber    Wkend    RushHR    Site      Temp     Hum    WS    ImpactWind    Deg      Bar      WS_HI     RF      UFPConc    lnUFP 
    _____    ______    ______    ______    ______    _____    ______    _________    _____    ______    _____    ______    ___    __    __________    ____    ______    _____    _____    _______    ______

     55.7    80.959    71.176    56.284    55.629    true     false         6        false    false     false    9.1111    27     21     railway        45      1032    true     false     11850     9.3801
    54.55     86.04    72.115    56.148     54.21    true     false         6        false    false     false       9.5    25     23     railway      67.5      1032    true     false     13050     9.4765
     56.5    87.401    74.502    59.194    55.401    true     false         6        false    false     false       9.5    25     23     railway      67.5      1032    true     false      9390     9.1474
    56.25    88.284    77.218    58.492    55.271    true     false         6        false    false     false       9.5    25     23     railway      67.5      1032    true     false      7740     8.9542
    61.55    96.355    81.347    62.264    59.521    true     false         6        false    false     false       9.5    25     23     railway      67.5      1032    true     false      5780     8.6622
     56.8    88.414    77.233    59.283    54.997    true     false         6        false    false     false       9.5    25     23     railway      67.5      1032    true     false      5895     8.6819
     55.6    84.186    74.424    58.529    54.151    true     false         6        false    false     false    9.2222    24     25     railway      67.5    1031.9    true     false      5570     8.6252
     53.2    77.159    71.649    55.711    52.469    true     false         6        false    false     false    9.2222    24     25     railway      67.5    1031.9    true     false      5480     8.6089
     53.5    81.756    72.694    56.928    52.419    true     false         6        false    false     false    9.2222    24     25     railway      67.5    1031.9    true     false      4730     8.4617
       56     93.19    79.098    58.817    54.379    true     false         6        false    false     false    9.2222    24     25     railway      67.5    1031.9    true     false      4030     8.3015
    57.25    93.925    80.813    58.982    55.997    true     false         6        false    false     false    9.2222    24     25     railway      67.5    1031.9    true     false      4640     8.4425
    54.95    84.922    71.069    59.342     53.42    true     false         6        false    false     false    9.1667    24     26     other        22.5    1031.9    true     false      4705     8.4564
       56    88.818    73.952    59.295    54.738    true     false         6        false    false     false    9.1667    24     26     other        22.5    1031.9    true     false      4725     8.4606
    55.05    87.831    72.037    58.687    53.735    true     false         6        false    false     false    9.1667    24     26     other        22.5    1031.9    true     false      5020     8.5212
     53.4    80.796    68.165    55.232    53.331    true     false         6        false    false     false    9.1667    24     26     other        22.5    1031.9    true     false      7685      8.947
    54.05    82.048    72.777    57.595    53.227    true     false         6        false    false     false    9.1667    24     26     other        22.5    1031.9    true     false      5685     8.6456

[Douglas Leaffer]

Thanks Stephen, worked perfectly !