When running phpBB 3.0.13-PL1 under php version 5.4 +, going to the "administrator panel, SYSTEM tab, and clicking MODULE MANAGEMENT, administrator control panel" generates lots of E_STRICT errors (static vs non-static) in module /acp/acp_modules.php at line 630.

The solution I have adopted is to change the code thus:
Replace lines 629 - 630 with:
// We use zero as the forum id to check - global setting.
(new p_master)->module_auth($row['module_auth']);
if ('p_master' != 0)
// if (!p_master::module_auth($row['module_auth'], 0))

This seems to fix the problem caused by php 5.4's interpretation of calls with static vs non-static classes