Btukfyl

I have upgraded Windows from 7 to 10. When I am compiling some latex files, which were already built in Windows 7 and used to work fine - now in Windows 10 I am getting this error message for some equations:

! Package ucs Error: Unknown Unicode character 8289 = U+2061,

(ucs)                possibly declared in uni-32.def.

(ucs)                Type H to see if it is available with options.

Using XeLaTex works well, but I prefer compiling tex files, to do any online edits.

Here is an example...
When compiling the below tex file, eq1 and eq2 are fine, while eq3 and eq4 are not. Why and how can this tex file be compiled "in windows 10" without getting a Unicode error?

documentclass[12pt,a4paper]{article} 

usepackage[utf8x]{inputenc}

usepackage{ucs}



begin{document}



begin{equation}label{eq 1}

F=W_{A}*M_{A}+W_{B}*M_{B}+..+W_{N}*M_{N}

end{equation}



begin{equation}label{eq 2}

RR=frac{dP(t)}{dt}=frac{P(t)-P(t-D)}{D}

end{equation}



begin{equation}label{eq_3}

X_{Scaled}=a+ frac{[x-min⁡(X)]}{[max⁡(X)-min⁡(X)]}*{b-a}

end{equation}



begin{equation}label{eq_4}

 X_{Standardized}= frac{[x-mean⁡(X)]}{std(X)}

 end{equation}



 end{document}

Your file contains hidden characters that LaTeX can't deal with, copy-paste in a good editor to see it. The following image shows these hidden characters shown as f() after min, max, and mean, remove these and recompile. Also min and max are typset in up roman, also mean and std.

documentclass[12pt,a4paper]{article} 

usepackage[utf8x]{inputenc}

usepackage{ucs,amsmath}



begin{document}



begin{equation}label{eq 1}

F=W_{A}*M_{A}+W_{B}*M_{B}+..+W_{N}*M_{N}

end{equation}



begin{equation}label{eq 2}

RR=frac{dP(t)}{dt}=frac{P(t)-P(t-D)}{D}

end{equation}



begin{equation}label{eq_3}

X_text{Scaled}=a+ frac{[x-min(X)]}{[max(X)-min(X)]}*{b-a}

end{equation}



begin{equation}label{eq_4}

 X_text{Standardized}= frac{[x-mathrm{mean}(X)]}{mathrm{std}(X)}

 end{equation}



 end{document}

The correct output:

Compiling your code under LuaLaTeX (while also loading the unicode-math package) yields the following screenshot for equations 3 and 4:

I've highlighted the four occurrences of U+2061. Why is this character in your tex file to begin with?

I believe you should re-write your code using min and max along the following lines (to be compiled under pdfLaTeX):

documentclass[12pt,a4paper]{article} 

usepackage{ucs}   % is this really needed?

usepackage{amsmath}

DeclareMathOperator{mean}{mean}

DeclareMathOperator{std}{std}



begin{document}

begin{equation}label{eq 1}

F=W_{A}*M_{A}+W_{B}*M_{B}+dots+W_{N}*M_{N}

end{equation}



begin{equation}label{eq 2}

RR=frac{dP(t)}{dt}=frac{P(t)-P(t-D)}{D}

end{equation}



begin{equation}label{eq_3}

X_{mathrm{Scaled}}=a+ frac{[x-min(X)]}{[max(X)-min(X)]}*{b-a}

end{equation}



begin{equation}label{eq_4}

 X_{mathrm{Standardized}}= frac{[x-mean(X)]}{std(X)}

end{equation}

end{document}