UnFormat.lsp does not work in Autocad 2021

[Nikon]

This code does not work in Autocad 2021 (localized version), the selected MText  is being deleted. 
How can this be fixed?
 

; UnFormat MText, MLeader, Table - strip formatting contol codes from texts
;
; based on Lee Mac's UnFormat string - www.lee-mac.com/unformatstring.html
; CAD Studio, 2018, www.cadstudio.cz  www.cadforum.cz
;
;
(vl-load-com)

;;-------------------=={ UnFormat String }==------------------;;
;;                                                            ;;
;;  Returns a string with all MText formatting codes removed. ;;
;;------------------------------------------------------------;;
;;  Author: Lee Mac, Copyright © 2011 - www.lee-mac.com       ;;
;;------------------------------------------------------------;;
;;  Arguments:                                                ;;
;;  str - String to Process                                   ;;
;;  mtx - MText Flag (T if string is for use in MText)        ;;
;;------------------------------------------------------------;;
;;  Returns:  String with formatting codes removed            ;;
;;------------------------------------------------------------;;

(defun LM:UnFormat ( str mtx / _replace rx )

    (defun _replace ( new old str )
        (vlax-put-property rx 'pattern old)
        (vlax-invoke rx 'replace str new)
    )
    (if (setq rx (vlax-get-or-create-object "VBScript.RegExp"))
        (progn
            (setq str
                (vl-catch-all-apply
                    (function
                        (lambda ( )
                            (vlax-put-property rx 'global     actrue)
                            (vlax-put-property rx 'multiline  actrue)
                            (vlax-put-property rx 'ignorecase acfalse) 
                            (foreach pair
                               '(
                                    ("\032"    . "\\\\\\\\")
                                    (" "       . "\\\\P|\\n|\\t")
                                    ("$1"      . "\\\\(\\\\[ACcFfHLlOopQTW])|\\\\[ACcFfHLlOopQTW][^\\\\;]*;|\\\\[ACcFfHLlOopQTW]")
                                    ("$1$2/$3" . "([^\\\\])\\\\S([^;]*)[/#\\^]([^;]*);")
                                    ("$1$2"    . "\\\\(\\\\S)|[\\\\](})|}")
                                    ("$1"      . "[\\\\]({)|{")
                                )
                                (setq str (_replace (car pair) (cdr pair) str))
                            )
                            (if mtx
                                (_replace "\\\\" "\032" (_replace "\\$1$2$3" "(\\\\[ACcFfHLlOoPpQSTW])|({)|(})" str))
                                (_replace "\\"   "\032" str)
                            )
                        )
                    )
                )
            )
            (vlax-release-object rx)
            (if (null (vl-catch-all-error-p str))
                str
            )
        )
    )
)
;-----------------

(defun doUnformatTable (table / rowCounter colCounter)
 (setq rowCounter (vla-Get-Rows table))
 (repeat rowCounter
 (setq rowCounter (1- rowCounter))
 (setq colCounter (vla-Get-Columns table))
 (repeat colCounter
  (setq colCounter (1- colCounter))
  (setq cellType (vla-GetCellType table rowCounter colCounter))
  (if (= cellType acTextCell)(progn
         (setq cellText (vla-GetText table rowCounter colCounter))
         (if (/= cellText "")
          (vla-SetText table rowCounter colCounter (LM:UnFormat cellText T)))
  ))
 ) ; rep
 ) ; rep
)

(defun c:UNFORMAT (/ ss ssl cnt en xxobj otyp txr ntx)
 (princ "\nSelect MTEXTs/DIMENSIONs/MLEADERs/TABLEs: ")
 (setq ss (ssget '((0 . "MTEXT,DIMENSION,MULTILEADER,ACAD_TABLE"))))
 (if (and ss (> (setq ssl (sslength ss)) 0))(progn
  (setq cnt 0)
  (repeat ssl
    (setq en (ssname ss cnt))
	(setq obj (vlax-ename->vla-object en))
	(setq otyp (cdr (assoc 0 (entget en)))) ; (vla-get-objectname obj))
	(cond
	 ((= otyp "MTEXT")(vla-put-TextString obj (LM:UnFormat (vla-get-TextString obj) T))) ; AcDbMText
	 ((= otyp "DIMENSION")(vla-put-TextOverride obj (LM:UnFormat (vla-get-TextOverride obj) T))) ; AcDbRotatedDimension, AcDbAlignedDimension
	 ((= otyp "MULTILEADER")(vla-put-TextString obj(LM:UnFormat (vla-get-TextString obj) T))) ; AcDbMLeader
	 ((= otyp "ACAD_TABLE")(doUnformatTable obj)) ; AcDbTable
	)
	(setq cnt (1+ cnt))
  ) ;rep
 )
 (princ "\nNothing selected!")
 ) ;if
 (princ)
)

(princ "\nUNFORMAT loaded.")
(princ)