ring, 122 bytes

Result

WA

Duration

782ms

Code [DL]

give s p=substr(s,:T)while 1 give s see copy(" ",p-1)?1 q=substr(s,:K)if q see copy(" ",q-1)see copy(:1,p-q)?1 exit ok end

stdin

                            T                     
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
          K                                       

stdout

/tmp/code.ring Line (1) Error (C3) : Unclosed control strucutre, 'ok' is missing
/tmp/code.ring Line (1) Error (C4) : Unclosed control strucutre, 'end' is missing
/tmp/code.ring errors count : 2 

stderr

strace