In asterisk Asterisk 1.8.15-cert5 you can see a lot or errors like that.

rc_avpair_new: unknown attribute 1490026597

I solved by unloading those Asterisk unused modules (loaded by default).
cel_radius
crd_radius

To solve in /etc/asterisk/modules.conf add these lines.

[modules]
autoload=yes
noload => cdr_radius.so
noload => cel_radius.so
....

After that.

amportal restart

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