Bug ID 996781: Mcpd failed with the error "Can't load vector structure"

Last Modified: Oct 19, 2025

Affected Product(s):
BIG-IP TMOS(all modules)

Known Affected Versions:
15.1.5, 15.1.5.1, 15.1.6, 15.1.6.1, 15.1.7, 15.1.8, 15.1.8.1, 15.1.8.2, 15.1.9, 15.1.9.1, 15.1.10, 15.1.10.2, 15.1.10.3, 15.1.10.4, 15.1.10.5, 15.1.10.6, 15.1.10.7, 15.1.10.8

Opened: Feb 23, 2021

Severity: 2-Critical

Symptoms

/var/log/ltm may contain error like this "Can't load vector structure()" Mcpd crashes.

Impact

Traffic disrupted while mcpd restarts.

Conditions

-- ACLs with large number of ACEs -- Large Access policy items

Workaround

None

Fix Information

None

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips