Troubleshooting - Temp file does not find a variable

Good evening everyone. I have the following code

Code:

use "Dataset.dta", replace

drop if 5*365>dis_end
tempfile A0
save `A0'

// Panel a

use `A0',clear
keep if 5*365<=dis_end
forvalue dfe = 1/5 {  //
 g         c_`dfe' = ned>`dfe'*365/2 if !mi(ned)
 replace c_`dfe' = 1                 if  mi(ned)
}
keep c_*
collapse (mean) c_*
 duplicates drop
g n =1
 reshape long  c_, i(n) j(week)
drop n
replace week = week/2
g cd_ = int(c_*1000)/1000
twoway ///
(line c_ week, lc(black)     lp(dash)) ///
(line c2 week, lc(black)     lp(dash) ) ///
(connect c_ week, lcolor(black) mcolor(black) msize(vsmall)) ///
(scatter c_ week if int(week)==week, mcolor(black) msize(vsmall) mlabel(cd_) mlabang(90)) ///
,  leg(off) ytitle("Survival rate") xtitle("Years since layoff") ///
xline(30 39, lp(dash) lcolor(gs10)) yline(0, lcolor(gs10))  
 graphregion(fcolor(white))  xl(1(1)5, grid) ylabel(0(.03).2, grid) ///   
 subtitle("Survival Rate (Prob. of Remaining Unemployed)",  size(m)) ///
 subt("Panel a") xtitle("Weeks since layoff")

keep c_ week
rename c_ survlevel
merge 1:1 week using `A1', nogen
tempfile A1
save    `A1', replace

My problems lies at the end. I think the very last line returns a "invalid file specification" error. I am reviewing the code and maybe there is a previous error in there, but does anyone see anything obvious that could prompt this error? Is there any way to open `A1' in its state before the last line for inspection?