Apps not updating/downloading properly?

Hello guys. I have an HTC One V. I have a problem which is really frustrating me! I was wondering if anybody can help me out with my situation. So, my apps won't update or download properly from the Google Play store. When I try, it says something like, "package file is invalid" or "Insufficient storage memory." This is really frustrating me! I did a factory reset thinking that it would solve the problem, but it didn't! I'm still having the same issue! Does anybody have any suggestions for me? Is this a problem with my phone itself? And how I fix this? Somebody please help!

Are you sure that you are logged into your Play account? If yes, try creating another gmail account and use it for Play. I am assuming that you have no issue getting to a web site using browser and your email app is working.

Yes, I am definitely logged into my Play account. Okay, I will try that out & let you know if it works. Thanks! And no, I am not having any problems getting to the browser or email app.

I tried making another Gmail account & using it for Play, but still nothing worked! ):