OK, The story gets more interesting. Some additional details/observations. This issue pops up once a week on Thursday night. I run a five person PR in v2018 ADV at that time. And EVERY week, this error message appears immediately AFTER I print the PR checks. Tonight I realize the coincidence. I finish the PR cycle in STD mode, then reboot the server. Run the PR a second time. Import the hours, run the PR calc, switch to manual taxes and change all five employee's state taxes to whole dollar amounts (in IA, the state does not want you to report cents, in prior versions of PR you could elect whole dollar state deduction, in 2018 you can't). Rerun the calc and print the audit report. Print the tax summary. Print the checks to a PDF. The error appears again before I can print the check register.
I do NOT have the v2018 client installed on another workstation or server because I am avoiding the Crystal reports issue (uninstall all prior versions & drop the .config file in the home directory of prior versions). So I don't know if this would happen on another workstation. As noted, I don't have the connection issue in STD mode. It happens with the CS ODBC on or off for the user. It occurs whether I print on paper or to a PDF driver.
I have cycled through various scenarios five times tonight. It blows every time immediately after check printing.