[abawany]

I remember performing the periodic AppData cleanup in 2009/2010 but haven't had to do that in the last few years. It was during that time that the chat delay issues were very common as well. From my point of view, while the Microsoft takeover and remake initially brought difficulties with login, the recent versions were not too bad apart from the Windows 8 Store version mess. But that is just my experience.

While I personally don't use the chat functionality that often anymore, the few times I have used it (say when an interview was being done over Skype), it worked ok but I realize that is hardly a high-use model. I agree that other messaging solutions such as Hangouts, HipChat, Slack, GroupMe, and etc. appear to perform much more seamlessly without needing to be aware of idiosyncrasies.

[Coding_Cat]

For me their still the occasional problem. Perhaps it is related to Windows 7?

[abawany]

Unfortunately, I can't say - I use it on Windows 7 and Windows 8.1, along with Android without issues. One thing I do that Skype appears to discourage is restart the application. This means don't allow it to launch on startup, I don't save my password (this is my practice with most apps), and I kill it if I know I won't need it; the latter is not practical if you need to be in constant touch with teams. I am not sure if any of this is a factor in my experience.

[Shorel]

In my experience, it happens if your computer's local time is not set up correctly.