SLA recalculation breaks when a single issue cannot be recalculated

Issue Summary

SLA recalculations fail on particular issues and the whole recalculation batch will be interrupted. Typically, recalculation fails when re-indexing the issue fails (error message "Indexing failed for Issue - '123456'").

Steps to Reproduce

So far no stable reproduction steps have been found.

Expected Results

All SLAs are updated

Actual Results

Some SLAs are not updated. The "! Update" link on the SLA project settings page doesn't disappear.

Workaround

Archive the issue(s) that cannot be recalculated.