I have reinstall flarum used by "composer create-project flarum/flarum . --stability=beta",no extension.
why,
mysite.com/admin#/mail
chrome errors:
MailPage.js:32 Uncaught TypeError: Object.keys(...).flatMap is not a function
at MailPage.js:32
at mithril.js:2033
at l (mithril.js:2004)
at c (mithril.js:2024)
at St.n.resolve (mithril.js:1941)
at mithril.js:1976
at Array.map (<anonymous>)
at u (mithril.js:1974)
at mithril.js:2051
at l (mithril.js:2004)
(anonymous) @ MailPage.js:32
(anonymous) @ mithril.js:2033
l @ mithril.js:2004
c @ mithril.js:2024
St.n.resolve @ mithril.js:1941
(anonymous) @ mithril.js:1976
u @ mithril.js:1974
(anonymous) @ mithril.js:2051
l @ mithril.js:2004
(anonymous) @ mithril.js:2048
l @ mithril.js:2004
c @ mithril.js:2024
St.n.resolve @ mithril.js:1941
(anonymous) @ Application.js:302
(anonymous) @ mithril.js:2033
l @ mithril.js:2004
c @ mithril.js:2024
St.n.resolve @ mithril.js:1941
(anonymous) @ mithril.js:1976
u @ mithril.js:1974
(anonymous) @ mithril.js:2051
l @ mithril.js:2004
(anonymous) @ mithril.js:2048
l @ mithril.js:2004
c @ mithril.js:2024
St.n.resolve @ mithril.js:1941
t.onload.t.onerror @ mithril.js:2272
n.onreadystatechange @ mithril.js:2153
XMLHttpRequest.send (async)
(anonymous) @ mithril.js:2191
(anonymous) @ mithril.js:2199
m.request @ mithril.js:2288
e.request @ Application.js:302
n.init @ MailPage.js:23
t @ Component.js:65
e @ Page.js:8
e @ MailPage.js:9
(anonymous) @ mithril.js:1453
m.mount.m.module @ mithril.js:1513
(anonymous) @ mithril.js:1760
pt @ mithril.js:1618
e.(anonymous function) @ mithril.js:1637
m.route @ mithril.js:1641
e.mount @ Application.js:161
n.mount @ AdminApplication.js:37
e.boot @ Application.js:140
(anonymous) @ admin:88
