Would be benefical to add a sample txt file so someone can provide you the exact code. What kind of error are you getting? Did you try the built in 'import data' option which can also generate a script for you?
Example script generated by matlab for your example:
%% Setup the Import Options and import the data
opts = delimitedTextImportOptions("NumVariables", 6);
% Specify range and delimiter
opts.DataLines = [2, Inf]; % 1 is the name of the column, VariableNames
opts.Delimiter = ";";
% Specify column names and types
opts.VariableNames = ["STATIONS_ID", "MESS_DATUM", "QN", "FF_10", "DD_10", "eor"];
opts.VariableTypes = ["double", "double", "double", "double", "double", "categorical"];
% Specify file level properties
opts.ExtraColumnsRule = "ignore";
opts.EmptyLineRule = "read";
% Specify variable properties
opts = setvaropts(opts, "eor", "EmptyFieldRule", "auto");
% Import the data
tbl = readtable("C:\New Text Document.txt", opts);
%% Convert to output type
STATIONS_ID = tbl.STATIONS_ID;
MESS_DATUM = tbl.MESS_DATUM;
QN = tbl.QN;
FF_10 = tbl.FF_10;
DD_10 = tbl.DD_10;
eor = tbl.eor;
