In contract MPHMinter, the function distributeFundingRewards does not check whether the contract itself is the owner of mph. If the contract is not the owner of mph, mph.ownerMint could revert, causing functions such as withdraw, rolloverDeposit, payInterestToFunders in the contract DInterest to revert as well.
Recommend adding a mph.owner() != address(this) check as in the other functions (e.g., mintVested).
ZeframLou (88mph) confirmed:
