Diagnosis
Company code MARS is not assigned to a field status variant.
System Response
G/L accounts cannot be maintained in company code MARS.
Procedure
Assign company code MARS to a field status variant.
SOLUTION :
STEP 1: Ensure Field Status Variant is already Created,
If not then create it by following this path: https://www.gauravconsulting.com/post/field-status-variant-in-sap-s-4-hana
STEP 2: Follow the below Path or Go to T. code OBC5

STEP 3: Provide Field Status Variant for your Company Code

Regards,
Adharsh KS