What changed in TeXForm in V 14.1?

Question

In Version 14.1 on windows 10 I get this error calling TeXForm on solution obtained from DSolve. No error in V 14. This is known error. see how-to-catch-this-error-from-texform-texformunspt

A workaround is to use InputForm but this produces bad Latex.

The question is: What changed in V 14.1 to cause this new TeXForm error for this specific example which used to work OK in V 14.0?

ode = D[y[x], {x, 3}] + 3*D[y[x], {x, 2}] - 9*D[y[x], x] - 5*y[x] == 0;
sol = DSolve[ode, y[x], x];
TeXForm[sol]

Gives

TeXForm::unspt

error:

TeXForm of DynamicModuleBox[{Typeset`HolonomicAttached$$},FrameBox[ButtonBox[GridBox[{{FEPrivate`Switch[Root,etc...

Below is screen shot comparing the output from V 14.

Version 14.1

Workaround is

ode = D[y[x], {x, 3}] + 3*D[y[x], {x, 2}] - 9*D[y[x], x] - 5*y[x] == 0;
sol = DSolve[ode, y[x], x];
TeXForm[InputForm@sol]

But the Latex now is now bad.

Version 14.0

May be someone knows some setting in Frontend changed in V 14.1 to cause this? Has there been changes made by WRI in TeXForm in V 14.1 from V 14.0 ? Could the new Semantic Highlighting in V 14.1 have anything to do with this?

Update

I think now it is related to the RooT formating? I found second example giving same error and it also has same Root type expression in the solution being given to TeXForm

ode = D[y[t], {t, 4}] + 4*D[y[t], {t, 3}] + 3*y[t] == t
sol = DSolve[ode, y[t], t]

TeXForm[sol]

InputForm[sol]

gives

{{y[x] -> E^(x*Root[-5 - 9*#1 + 3*#1^2 + #1^3 & , 1, 0])*C[1] + E^(x*Root[-5 - 9*#1 + 3*#1^2 + #1^3 & , 2, 0])*
     C[2] + E^(x*Root[-5 - 9*#1 + 3*#1^2 + #1^3 & , 3, 0])*C[3]}}

And TeXForm does not like something about the above. Same for first example above.

Answer 1

Well, it's a bug. They've changed MakeBoxes of Root objects to implement the new formatting, but they didn't make the changes for the TeXForm. As a simple workaround, you can use:

BoxForm`$UseUnifiedRootTemplateBox = False;