[Xita Mitra]

My phone is new Xperia z3 compact. I started installing softwares through third party stores pretty fine, but then it suddenly stopped.

It currently installs apps from Google play, but if I download an app from a third party software or a website, when the package is parsing the "next" and "install" buttons won't click and my only option is to.click cancel.

I tried resetting the phone and the problem was resolved but then it came back again.

I deleted store and the third party app cache but it didn't help.

Restart doesn't help either.

[SpookDroid]

Is your 'unknown sources' installation permission still checked in the Settings?

[Xita Mitra]

Is your 'unknown sources' installation permission still checked in the Settings?

That's strange! I checked that multiple times and sure enough, it was checked. But now that you mentioned it, I thought why not check and uncheck it once (like how restarting windows is famous for solving everything!) and it started working again!! Is this a known issue that you have to check and uncheck that option every once in a while?

Thank you very much Spookdroid!

[SpookDroid]

Not a problem, glad I could help!

It's not an issue per se, but I've read about this from time to time. For some reason SOME phones decide to un-check the Unknown Sources installation on their own at random times. It's not widespread though, but if that happens again, you know why at least.