Сталкивался с такой проблемой, московский саппорт сослался на то, что поменялось поведение ASE в 15.5


If the user is creating a #tmptble, then dropping it and recreating it again ALL IN ONE BATCH, it won't work.
The reason is that when the query is parsed and normalized, each object reference is replaced by an object id.
The two creates would generate two different ids, ASE doesn't know which to associate with the name later in the batch
(batches could contain conditional logic that caused the drop/2nd create to not execute)
To keep things simple for the parser, it isn't allowed


1> create table #tempabc (a int)
2> select * from #tempabc
3> drop table #tempabc
4> create table #tempabc ( b int)
5> go
Msg 12822, Level 16, State 1:
Server 'MyServer', Line 4:
Cannot create temporary table '#tempabc'. Prefix name '#tempabc' is already in
use by another temporary table '#tempabc'.



If the create temptable commands are run in two batches, then they are running fine:
=======================

1> create table #tempabc (a int)
2> select * from #tempabc
3> drop table #tempabc
4> go
a
-----------

1> create table #tempabc (b int)
2> select * from #tempabc
3> go
b
-----------