The issue appears to be related to Oracle, so my assumption is that you have an on premise instance and database not hosted by Adobe. I looked internally on my end but have not seen any instance where this error has been seen previously.
Oracle documentation around this error states the following:
ORA-24801: illegal parameter value in OCI lob function
Cause: One of the parameter values in the OCI lob function is illegal.
Action: Check every parameter in the OCI Lob function call to make sure they are correct. Offsets should be greater than or equal to one.
If you've checked, and it appears that all your parameters are coded properly and you still receive the ORA-24801, you may simply need to upgrade the client.
Have any upgrades to your environment or database taken place recently?
With the specific Campaign's did these work before or have they always failed?
And if they worked previously were any changes made?
Are you only seeing these errors or are your colleagues seeing them as well?
If it's just you, did you try performing a hard and soft clear of your local cache?
Something else you could do is export the Campaigns and workflows in question and import them into your non-production environment and see if the same error occurs.