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It would depend on your OS, version, I.E. Windows, Mac, Android etc. and maybe which proxy.
There have been some of these "glitches" that seem to come and go without any reason. Hopefully upcoming the Epic update will address this.
I would close Epic, then restart. If that doesn't help reset Epic under Advanced/ Preferences. You might switch the country of the proxy. Some of the time 403 ERROR is a temporary occurrence.
If I think of any thing else. I'll post it.
Good luck
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