Rolled Back Transaction Error when saving Columns

After customising the Columns for your pdfs you may run into this error message after hitting the Save Config button:

"Something went wrong while saving this configuration: Rolled back transaction has not been completed correctly."

We traced this issue to the Amasty Admin Actions Log extension which seems unable to handle the data in the Columns Field. Until Amasty is able to address this we suggest turning off the Log Actions functionality while the pdfs are configured. As we believe this is not a common occurrence once configured this setting can get re-enabled after.