Sabrina,
what SQL Anywhere 12 build are you using on the workstations (shown in Sybase Central's "Help/About" window - or "Hilfe/Info über..." in a German version)?
And what version are you using on the database server (use "select @@version" in DBISQL)?
With SA 12.0.1.4278, I cannot reproduce that problem, a maintenance plan is created without issues. (@Breck: And the cited error message is really not telling anything relevant: "Sybase Central has encountered a problem and must be closed...").
Does the problem also appear when switching to use the English locale? - To do so, run "%SQLANY12%\bin64\dblang EN" in a cmd window.
Note, whereas you need Sybase Central to create maintenance plans, they are really only some wrapper around the according events, so you might be able to create the events directly within DBISQL without these issues.
(In case you have an existing maintencance plan, the according event is named like the maintenance plan with an "_event" suffix, so for the plan "MT_MyFullBackup", you might have an event "MT_MyFullBackup_event".)
Further hints may be found in the SQL Anywhere forum here:
Questions Tagged With maintenance-plan - SQLA Forum
Best regards
Volker
