Skip to main content

This content has been archived and is no longer being updated. Links may not function; however, this content may be relevant to outdated versions of the product.

Support Article

UnresolvedAssemblyErrors shut down agents



After skimming and migrating a set of rulesets, agents encounter UnresolvedAssemblyErrors and shut down.

Error Messages

Batch activity "<Your_Activity>" threw: Invalid expression or reference: No candidates found [possible function name, ruleset/version or number of parameter problem] 
at com.pega.pegarules.priv.FUAUtil.throwUnresolvedAssemblyError(

ERROR   - Agent [<Your_Agent>] activity [<Your_Activity>] queue number [] disabled due to execution errors ErrorMsg: ** <Your_Function> -InvalidExpression 
No candidates found [possible function name, ruleset/version or number of parameter problem]     for Rule-Utility-Function in ruleset list <null> expected since isEditing is false ruleset = <Your_Ruleset> library = <Your_Library> functionName = <Your_Function> parameters = [ ]

Steps to Reproduce

Migrate the skimmed  rules.

Root Cause

A defect or configuration issue in the operating environment.
The function in the error messages did not compile correctly. This resulted in an error which had to display when the First Use Assembly (FUA) of the migrated rules ran. Hence, the agents shut down.


Perform the following local-change:

Revalidate and save the function (in question).

Published April 12, 2019 - Updated October 8, 2020

Was this useful?

0% found this useful

Have a question? Get answers now.

Visit the Collaboration Center to ask questions, engage in discussions, share ideas, and help others.

Did you find this content helpful?

Want to help us improve this content?

We'd prefer it if you saw us at our best.

Pega Community has detected you are using a browser which may prevent you from experiencing the site as intended. To improve your experience, please update your browser.

Close Deprecation Notice
Contact us