CALLERPRES dialplan function was removed from Asterisk as of version 17.
Issabel 5 write settings with CALLERPRES command in "extensions_additional.conf" (contexts [ext-trunk], [ext-did], [macro-outbound-callerid]) because every incoming call show error in console: "Function CALLERPRES not registered".
I believe that replacing them all with CALLERID will fix the problem, but it is better done that with new patch in issabel, than as crone task.
https://wiki.asterisk.org/wiki/display/AST/Function_CALLERPRES
Let somone told to support for this issue.
Additionally it is impossible edit incoming number (strip or add number) in some context.
