unable to edit videos in arender

i have tried on stage and prod, and see the same thing: "Error: could not open document.".
Inspector shows:
arendergwt-0.js:2313 Tue Oct 02 08:04:57 GMT-500 2018 com.arondor.viewer.client.controllers.impl.ErrorControllerImpl
SEVERE: doOpenDocument() : Could not open documentcom.arondor.viewer.client.api.document.DocumentNotAvailableException: Document id : b64_ZGVmYXVsdCwxMzliNTZkMS04MDY3LTRiYzgtOWNiNi1hOGZhMDIxZmUxYjUsZmlsZTpjb250ZW50TWljaGVsZUBuYm0uY29t had a parsing exception, please check rendition logs for more details
at Unknown.Qd(arendergwt-0.js)
at Unknown.Nd(arendergwt-0.js)
at Unknown.Ud(arendergwt-0.js)
at Unknown.new a2(arendergwt-0.js)
at Unknown.c2(arendergwt-0.js)
at Unknown.Brf(arendergwt-0.js)
at Unknown.OU(arendergwt-0.js)
at Unknown.dqf(arendergwt-0.js)
at Unknown.Iqf(arendergwt-0.js)
at Unknown.Qae(arendergwt-0.js)
at Unknown.bbe(arendergwt-0.js)
at Unknown.eval(arendergwt-0.js)
at Unknown.h_d(arendergwt-0.js)
at Unknown.k_d(arendergwt-0.js)
at Unknown.eval(arendergwt-0.js)

jhf @ arendergwt-0.js:2313
Ihf @ arendergwt-0.js:2215
Hhf @ arendergwt-0.js:1878
kVf @ arendergwt-0.js:930
wdb @ arendergwt-0.js:2311
bcd @ arendergwt-0.js:2161
dcd @ arendergwt-0.js:1782
Zbd @ arendergwt-0.js:1783
acd @ arendergwt-0.js:1864
jcb @ arendergwt-10.js:3998
Jqd @ arendergwt-10.js:3998
rab @ arendergwt-10.js:3476
uab @ arendergwt-10.js:3998
Iqf @ arendergwt-0.js:2292
Qae @ arendergwt-0.js:1828
bbe @ arendergwt-0.js:2313
(anonymous) @ arendergwt-0.js:1691
h_d @ arendergwt-0.js:1244
k_d @ arendergwt-0.js:2155
(anonymous) @ arendergwt-0.js:2055
XMLHttpRequest.send (async)
Xae @ arendergwt-0.js:2264
xU @ arendergwt-0.js:2252
Eqf @ arendergwt-0.js:1965
Lrd @ arendergwt-10.js:3493
Xqd @ arendergwt-10.js:1581
Zqd @ arendergwt-10.js:3998
oab @ arendergwt-10.js:3262
mab @ arendergwt-10.js:3778
xqd @ arendergwt-10.js:1770
pbb @ arendergwt-10.js:3542
Ibb @ arendergwt-10.js:3998
nRc @ arendergwt-10.js:3998
tae @ arendergwt-0.js:2253
AKc @ arendergwt-10.js:3047
FKc @ arendergwt-10.js:3064
RKc @ arendergwt-10.js:3586
YKc @ arendergwt-8.js:958
GKc @ arendergwt-10.js:3430
KKc @ arendergwt-10.js:3998
Mv @ arendergwt-2.js:204
kcd @ arendergwt-0.js:2222
ncd @ arendergwt-0.js:2311
Iqf @ arendergwt-0.js:2292
Qae @ arendergwt-0.js:1828
bbe @ arendergwt-0.js:2313
(anonymous) @ arendergwt-0.js:1691
h_d @ arendergwt-0.js:1244
k_d @ arendergwt-0.js:2155
(anonymous) @ arendergwt-0.js:2055
XMLHttpRequest.send (async)
Xae @ arendergwt-0.js:2264
xU @ arendergwt-0.js:2252
Eqf @ arendergwt-0.js:1965
Nrd @ arendergwt-0.js:2164
yrd @ arendergwt-0.js:996
bcd @ arendergwt-0.js:2161
dcd @ arendergwt-0.js:1782
fcd @ arendergwt-0.js:509
icd @ arendergwt-0.js:2311
Iqf @ arendergwt-0.js:2292
Qae @ arendergwt-0.js:1828
bbe @ arendergwt-0.js:2313
(anonymous) @ arendergwt-0.js:1691
h_d @ arendergwt-0.js:1244
k_d @ arendergwt-0.js:2155
(anonymous) @ arendergwt-0.js:2055
XMLHttpRequest.send (async)
Xae @ arendergwt-0.js:2264
xU @ arendergwt-0.js:2252
Eqf @ arendergwt-0.js:1965
Ord @ arendergwt-0.js:2165
zrd @ arendergwt-0.js:789
Zbd @ arendergwt-0.js:1783
acd @ arendergwt-0.js:1864
Pu @ arendergwt-2.js:179
Hv @ arendergwt-2.js:84
Kv @ arendergwt-2.js:204
r0c @ arendergwt-10.js:883
jh @ arendergwt-10.js:1833
eh @ arendergwt-10.js:3587
hh @ arendergwt-10.js:3998
Qg @ arendergwt-10.js:3466
mh @ arendergwt-10.js:3339
pAb @ arendergwt-8.js:958
H$d @ arendergwt-0.js:2269
M$d @ arendergwt-0.js:418
h_d @ arendergwt-0.js:1244
k_d @ arendergwt-0.js:2155
(anonymous) @ arendergwt-0.js:2055
(anonymous) @ arendergwt-8.js:958
arendergwt.__installRunAsyncCode @ arendergwt.nocache.3.1.10-1.js:11
__gwtInstallCode @ arendergwt-0.js:1
A_d @ arendergwt-0.js:2150
$_d @ arendergwt-0.js:1282
(anonymous) @ arendergwt-0.js:1747
h_d @ arendergwt-0.js:1244
k_d @ arendergwt-0.js:2155
(anonymous) @ arendergwt-0.js:2055
(anonymous) @ 8.cache.js:1