Time in and out with Check mark to check out

Good morning

I was wonder if anyone can help me solve a formula error I scan a Id in colum A3 using this code in colum B3 =IF(A3="","",IF(LEN(A3)>6,VALUE(LEFT(A3,LEN(A3)-1)),A3))

then the name appears and the time shows in colum D3 using this code =IF(B3<>"",IF(D3="",NOW(),D3),"") and in colum E I have a check mark then it shows the output time in colum F using this formula =IF(B3<>"",IF(E3=TRUE,IF(F3="",NOW(),F3),""),"") Here is where I am having a error I want to know the difference between colum D3 and colum F3 in colum G3 showing the results after the check mark in colum E I have this formula In colum G =TEXT(F3-D3, "h:mm:ss") It works fine just when I copy the rest of the formula down the colum gives me a #value error but after using the check mark it shows the difference in time and disapears I just want to make it so it dont show the #value error.

I think I have to use a =if function I am new to excel and I am not sure what I am doing wrong in colum G3 so when I copy the formula down it dont show me the #value error