pa_project_assets_pub giving error when changing asset type

I am using pa_project_assets_pub to update the Asset Type from Estimated to Retirement Adjustment and getting this error "'&ASSET' cannot change Project Asset Type from or to RETIREMENT_ADJUSTMENT. I can do the same in EBS form for this project without any error.

Can Someone tell me why is this API giving error. Thanks a lot.

DECLARE

  E       VARCHAR2(1);

  x_p_id  NUMBER;

  x_p_num VARCHAR2(240);

  x_p_ref VARCHAR2(60);

  x_a_id  NUMBER;

  x_a_ref VARCHAR2(240);

  C       NUMBER;

  D       VARCHAR2(32000);

  R       VARCHAR2(32000);

BEGIN

  DELETE FROM ak_loader_temp;

  pa_project_pub.init_project;