It seems like you have project budgets integrated with GL budget.
For such integration you have to customize the Workflow of budget Account Generator . This process is generating the GL CCID for submitted budget lines.
It seems that the account generator of the budget does not cover the case of those three projects, and cannot generate accounting for them.
You need to check the setup of the accounting rules in the Workflow.
Make sure the workflow for budget "Project Budget Account Generation" is correctly set @ Account Generator Process
Also try to check from the projects-->budgets window, error message and the account which it is failing
mostly it would be a code combination id doesn't exist, define the code combinations in GL and then try resubmitting the project