Reading From Text File breaks midway - vbscript

Question

Resolved: All I had to do was add a sleep to the loop.
I have a text file which contains usernames and passwords which need to be logged in. I'm attempting to make a VBScript file to automate this process. The text file's syntax is
username
password
username
password
etc etc
and is a total of 738 lines.
The code I currently have is
Set objFSO = CreateObject("Scripting.FileSystemObject")
Set objFile = objFSO.OpenTextFile("C:\Users\Jacob\Desktop\logins.txt", ForReading)
Set WshShell = WScript.CreateObject("WScript.Shell")
Const ForReading = 1
Dim strUsername
Dim strPassword
wshshell.AppActivate "Notepad"
Do Until objFile.AtEndOfStream
strUsername = objFile.ReadLine
strPassword = objFile.ReadLine
wshshell.sendkeys strUsername
wshshell.sendkeys "~"
wshshell.sendkeys strPassword
wshshell.sendkeys "~"
Loop
which I'm using simply to make sure it works by having it write to a blank text file. (Later notepad will be replaced by the login executable, I already know that part works).
The code works fine until it hits line 221 of the text file, where it breaks. It exports a bunch of random garbage and then stops.
Any help is greatly appreciated.
Edit:
Here is the garbage text which comes at the end of the written text file. You can see that there are still remnants of what should come out.
.[redacted username].22bssddd2222ent000.2wlllkarsstt00....000h8b6b99b88uub2
.....ttttte0000mp00...gh.rrlll00225..gbu
.....0022sdg
[redacted password]
.proeflussssddd
..22le.pu6....225500s.gl.iteee.55.uuu.hmadttn..0dl
tsssssbeeee0000nsssss0000000ssssdssdbuuuz22dddd000buuu.jj2222
b4....3
.j00000000b
y.
bb.ddddssgg.2222ssgg05uuudbeeeeen......hh00222l11.....tdddd.nn
00000
ll0ssssau0s000ssssss
bbddddlll.ttttl......s
be
.o222
b.ddddddutttt
ll000buc11e000000utttt
bbb.eeeeee0000seeeee5
mmssss000000unnnttttnnn
bb000..s.dsssssss.fa000000
2
.....k000.4tnnn
.....bbbseeeu
.n.2te....s
7e9bbmv00000000tttteeee.mttseetnn2222222r0000000000.u.ddd0000000.111ddddge11111ssddddoo000.ssssssnnnn.uutnnn772
.bbg.......66teeb000000ee1114lrd00002222nsp

Answer 1

Two things you can try...
Try adding a call to WScript.Sleep 100 inside your loop after your call to SendKeys.
Instead of using AppActivate and SendKeys, you could try it where the script just writes the usernames and passwords to another file. This would rule out if the problem is being caused by SendKeys. Using SendKeys with this much data is fairly dangerous anyways. If anything at all goes wrong with Notepad getting focus and the keys start getting directed to another application it could have some very, very unintentional results.
Here is a modified copy of your script to write to a text file
Set objFSO = CreateObject("Scripting.FileSystemObject")
Set objFile = objFSO.OpenTextFile("logins.txt", ForReading)
Set objFile2 = objFSO.OpenTextFile("logins2.txt", ForWriting, true)
Set WshShell = WScript.CreateObject("WScript.Shell")
Const ForReading = 1, ForWriting = 2
Dim strUsername
Dim strPassword
Do Until objFile.AtEndOfStream
strUsername = objFile.ReadLine
strPassword = objFile.ReadLine
objFile2.Write strUsername & vbCrLf
objFile2.Write strPassword & vbCrLf
Loop
A couple of stylistic notes as well:
Define constants before you use them, preferably at the very top of the script. This keeps you and other from having to hunt them down later or thinking they haven't already been defined. It's not a big of a problem in a small script like this, but if you scripts starts getting bigger it could cause you headaches down the road.
Be consistent with Dim's. You defined strUsername and strPassword but you didn't define objFSO, objFile, or WshShell. I always recommend using Option Explicit to force you to define variables before using them. It helps you keep from making spelling mistakes and saves you a lot of headache in the long run.