I get "Datamodule1 is not ready".
Then, your global variable object Datamodule1 isn't yet created.
If Datamodule is a normal datamodule you added via Lazarus, it should be added in the automatically created forms/modules.
Could you check Project > Project Options under Project Options you have Forms.
Under Auto-create forms your should have your form and the DataModule1.
Is that DataModule1 the first, above your own form?
If not, move it up, above your form.
After that you should not get the Error-message anymore.
(Your problem could be that Form1.FormCreate is executed before the whole DataModule1 is created. In which case you get the SIGSEGV. Moving DataModule1 above Form1, you make sure DataModule1 exists before the Form1.FormCreate is executed.)