Error in action WriteTextToFile

can't create directory "U:/": no such file or directory
    while executing
"file mkdir $dir"
    (procedure "::InstallJammer::CreateDir" line 13)
    invoked from within
"::InstallJammer::CreateDir $dir"
    (procedure "::InstallJammer::actions::WriteTextToFile" line 25)
    invoked from within
"::InstallJammer::actions::$component $this"
Error in action WriteTextToFile

can't create directory "U:/": no such file or directory
    while executing
"file mkdir $dir"
    (procedure "::InstallJammer::CreateDir" line 13)
    invoked from within
"::InstallJammer::CreateDir $dir"
    (procedure "::InstallJammer::actions::WriteTextToFile" line 25)
    invoked from within
"::InstallJammer::actions::$component $this"
    while executing
"$obj execute"
    (procedure "::InstallJammer::ExecuteActions" line 62)
    invoked from within
"::InstallJammer::ExecuteActions $id -when $when"
    (procedure "::InstallJammer::NextCommand" line 8)
    invoked from within
"::InstallJammer::NextCommand .wizard 0262DEAC-15B7-483E-973F-A6FC7AC16747"
    ("uplevel" body line 1)
    invoked from within
"uplevel #0 [string map $map $command]"
    (procedure "_eval_command" line 22)
    invoked from within
"_eval_command $path $cmd"
    (procedure "Wizard::next" line 9)
    invoked from within
"Wizard::next .wizard 1"
    ("eval" body line 1)
    invoked from within
"eval [linsert $args 0 Wizard::$cmd .wizard]"
    (procedure ".wizard" line 1)
    invoked from within
".wizard next 1"
    ("eval" body line 1)
    invoked from within
"eval [list $info(Wizard) next] $args"
    ("next" arm line 3)
    invoked from within
"switch -- $command {
"back" {
if {![llength $args]} { set args 1 }
eval [list $info(Wizard) back] $args
}

"next" {
if {![llength $args]} { set args 1..."
    (procedure "::InstallJammer::Wizard" line 13)
    invoked from within
"::InstallJammer::Wizard next 1"
    (procedure "::InstallJammer::ExecuteActions" line 72)
    invoked from within
"::InstallJammer::ExecuteActions $id -when $when"
    (procedure "::InstallJammer::RaiseEventHandler" line 79)
    invoked from within
"::InstallJammer::RaiseEventHandler  .wizard"
    (command bound to event)