R12.0.6 : Patch 11686670 failing on 12.0.6

hello,

When trying to apply patch 11686670 on 12.0.6 Instance, we got this error :

Original copy is /appltech/appl/apps/apps_st/appl/admin/QSTECH/log/adrelink.lsv
New copy is /appltech/appl/apps/apps_st/appl/admin/QSTECH/log/adrelink.log

An error occurred while relinking application programs.
Continue as if it were successful [No] :

the adrelink.log shows :

========

l

d: 0706-005 Cannot find or open file:

/..../apps/apps_st/appl/sht/12.0.0/lib/ilog/6.2/libschedule.a

ld:open(): No such file or directory

ld: 0706-005 Cannot find or open file:

/..../apps/apps_st/appl/sht/12.0.0/lib/ilog/6.2/libsolveriim.a

ld:open(): No such file or directory