[SR-Users] Kamailio V4.2.5 append prefix to Request Uri problem.

Hello; i try to append prefix to $rU like below in Kamailio V4.2.5 . i get error even if i set string value. it works only when i append like that $rU="3002"+$rU; --------- 1 test------------ $var(prefix)=$avp(s:69); $rU=$var(prefix)+$rU; -FAILED ---------2 test ------------ $rU=$avp(s:69)+$rU; -FAILED ------- 3 test ------------ $rU=$avp(i:69)+$rU; -FAILED -------ERROR--------- May 29 12:06:57 group1-imslab11 /usr/local/sbin/kamailio[26196]: ERROR: pv [pv_core.c:2115]: pv_set_ruri_user(): str value required to set R-URI user May 29 12:06:57 group1-imslab11 /usr/local/sbin/kamailio[26196]: ERROR: <core> [lvalue.c:363]: lval_pvar_assign(): setting pvar failed May 29 12:06:57 group1-imslab11 /usr/local/sbin/kamailio[26196]: ERROR: <core> [lvalue.c:416]: lval_assign(): assignment failed at pos: (790,7-790,22) it work on Version 4.1.7 like below correctly; $rU=$avp(i:69)+$rU; Thanks Yasin