Workaround

First, I think that you refer about when you go in tty1 - Ctrl + Alt + F1.

Now, I think is happening what you said most likely because you have a strange character like ♦ (diamond suit character or the special badge for an askubuntu moderator) in ~/.bashrc or ~/.profile file or other file that contain various initialization commands.

As you can see in next image, I edited ~/.bashrc file puting inside ♦ character on a single line. As result, when I open the terminal it get the problem described by you:

It is happening the same when I go in tty1 with Ctrl + Alt + F1.

Files that contain initialization commands when a shell is invoked: /etc/profile, /etc/bashrc, ~/.bash_login, ~/.profile, ~/.bashrc, ~/.bash_aliases and maybe others. See Shell initialization files.

To quickly check if one of these files have something wrong inside you can use source command. For example:

source ~/.bashrc

Final solution

After inspecting /etc/profile from http://paste.ubuntu.com/5781361/, I found that on the line 31 there is "Right-To-Left Override" - ‮ unicode character. Just open /etc/profile file with sudo -H gedit /etc/profile, make sure to delete this strange character and the problem will disappear.

As amusement, in HTML for example, if you insert this unicode character using decimal code (‮) in front of a line, look what is happening:

‮This text is in arabic-english!

Another more generalized solution

We will find the exact command that causing the error using a "trap".

First, we have to make a new script file in ~/bin directory, let's call it lib.trap.sh (gedit ~/bin/lib.trap.sh), with following inside:

lib_name='trap'



lib_version=20130620

#changed from lib_version=20121026 found it at https://stackoverflow.com/a/13099228/2353900 to work well at initialization of the shell



stderr_log="/dev/shm/stderr.log"



#

# TO BE SOURCED ONLY ONCE:

#

###~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~##



if test "${g_libs[$lib_name]+_}"; then

    return 0

else

    if test ${#g_libs[@]} == 0; then

        declare -A g_libs

    fi

    g_libs[$lib_name]=$lib_version

fi





#

# MAIN CODE:

#

###~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~##



set -o pipefail  # trace ERR through pipes

set -o errtrace  # trace ERR through 'time command' and other functions

set -o nounset   ## set -u : exit the script if you try to use an uninitialised variable

set -o errexit   ## set -e : exit the script if any statement returns a non-true return value



exec 2>"$stderr_log"





###~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~##

#

# FUNCTION: EXIT_HANDLER

#

###~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~##



function exit_handler ()

{

    local error_code="$?"



    test $error_code == 0 && return;



    #

    # LOCAL VARIABLES:

    # ------------------------------------------------------------------

    #    

    local i=0

    local regex=''

    local mem=''



    local error_file=''

    local error_lineno=''

    local error_message='unknown'



    local lineno=''





    #

    # PRINT THE HEADER:

    # ------------------------------------------------------------------

    #

    # Color the output if it's an interactive terminal

    test -t 1 && tput bold; tput setf 4                                 ## red bold

    echo -e "

(!) EXIT HANDLER

"





    #

    # GETTING LAST ERROR OCCURRED:

    # ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ #



    #

    # Read last file from the error log

    # ------------------------------------------------------------------

    #

    if test -f "$stderr_log"

        then

            stderr=$( tail -n 1 "$stderr_log" )

            rm "$stderr_log"

    fi



    #

    # Managing the line to extract information:

    # ------------------------------------------------------------------

    #



    if test -n "$stderr"

        then        

            # Exploding stderr on :

            mem="$IFS"

            local shrunk_stderr=$( echo "$stderr" | sed 's/: /:/g' )

            IFS=':'

            local stderr_parts=( $shrunk_stderr )

            IFS="$mem"



            # Storing information on the error

            error_file="${stderr_parts[0]}"

            error_lineno="${stderr_parts[1]}"

            error_message=""



            for (( i = 3; i <= ${#stderr_parts[@]}; i++ ))

                do

                    error_message="$error_message "${stderr_parts[$i-1]}": "

            done



            # Removing last ':' (colon character)

            error_message="${error_message%:*}"



            # Trim

            error_message="$( echo "$error_message" | sed -e 's/^[ 	]*//' | sed -e 's/[ 	]*$//' )"

    fi



    #

    # GETTING BACKTRACE:

    # ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ #

    _backtrace=$( backtrace 2 )





    #

    # MANAGING THE OUTPUT:

    # ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ #



    local lineno=""

    regex='^([a-z]{1,}) ([0-9]{1,})$'



    if [[ $error_lineno =~ $regex ]]



        # The error line was found on the log

        # (e.g. type 'ff' without quotes wherever)

        # --------------------------------------------------------------

        then

            local row="${BASH_REMATCH[1]}"

            lineno="${BASH_REMATCH[2]}"



            echo -e "FILE:		${error_file}"

            echo -e "${row^^}:		${lineno}

"



            echo -e "ERROR CODE:	${error_code}"             

            test -t 1 && tput setf 6                                    ## white yellow

            echo -e "ERROR MESSAGE:

$error_message"





        else

            regex="^${error_file}$|^${error_file}s+|s+${error_file}s+|s+${error_file}$"

            if [[ "$_backtrace" =~ $regex ]]



                # The file was found on the log but not the error line

                # (could not reproduce this case so far)

                # ------------------------------------------------------

                then

                    echo -e "FILE:		$error_file"

                    echo -e "ROW:		unknown

"



                    echo -e "ERROR CODE:	${error_code}"

                    test -t 1 && tput setf 6                            ## white yellow

                    echo -e "ERROR MESSAGE:

${stderr}"



                # Neither the error line nor the error file was found on the log

                # (e.g. type 'cp ffd fdf' without quotes wherever)

                # ------------------------------------------------------

                else

                    #

                    # The error file is the first on backtrace list:



                    # Exploding backtrace on newlines

                    mem=$IFS

                    IFS='

                    '

                    #

                    # Substring: I keep only the carriage return

                    # (others needed only for tabbing purpose)

                    IFS=${IFS:0:1}

                    local lines=( $_backtrace )



                    IFS=$mem



                    error_file=""



                    if test -n "${lines[1]}"

                        then

                            array=( ${lines[1]} )



                            for (( i=2; i<${#array[@]}; i++ ))

                                do

                                    error_file="$error_file ${array[$i]}"

                            done



                            # Trim

                            error_file="$( echo "$error_file" | sed -e 's/^[ 	]*//' | sed -e 's/[ 	]*$//' )"

                    fi

                    

            echo -e "ROW, FILE:		${lines[2]   }

"



                    echo -e "ERROR CODE:	${error_code}"

                    test -t 1 && tput setf 6                            ## white yellow

                    if test -n "${stderr}"

                        then

                            echo -e "ERROR MESSAGE:

${stderr}"

                        else

                            echo -e "ERROR MESSAGE:

${error_message}"

                    fi

            fi

    fi



    #

    # PRINTING THE BACKTRACE:

    # ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ #



    test -t 1 && tput setf 7                                            ## white bold

    echo -e "

$_backtrace

"



    #

    # EXITING:

    # ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ #



    test -t 1 && tput setf 4                                            ## red bold

    echo "Exiting!"



    test -t 1 && tput sgr0 # Reset terminal



    exit "$error_code"

}

trap exit_handler ERR                                                  # ! ! ! TRAP EXIT ! ! !

#trap exit ERR                                                        # ! ! ! TRAP ERR ! ! ! 





###~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~##

#

# FUNCTION: BACKTRACE

#

###~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~##



function backtrace

{

    local _start_from_=0



    local params=( "$@" )

    if (( "${#params[@]}" >= "1" ))

        then

            _start_from_="$1"

    fi



    local i=0

    local first=false

    while caller $i > /dev/null

    do

        if test -n "$_start_from_" && (( "$i" + 1   >= "$_start_from_" ))

            then

                if test "$first" == false

                    then

                        echo "BACKTRACE IS:"

                        first=true

                fi

                caller $i

        fi

        let "i=i+1"

    done

}



return 0

Now, the only thing what you have to do is to put next line at the begining of the file /etc/profile (sudo -H gedit /etc/profile):

source '/home/<user_name>/bin/lib.trap.sh'

Change <user_name> with your user name. Like this, all the files that contain initialization commands when a shell is invoked will pass through the "trap".

To test if there is a wrong command in /etc/profile for example, run in terminal next commands:

bash
source /etc/profile

If something is wrong, like in this case, the result will be:

So, now we know for sure that there is a problem (command not found) in /etc/profile file at line 32 (it is not at the line 31 as above because we have inserted a new line at the beginning of the file).

Many thanks to Luca Borrione for his script from this answer that helped me to complete this generalized solution.