A RESTORE and REJECT of ACF2 usermod UM99901 is unable to happen without also doing a RESTORE for a lot of other ACF2 maintenance. How can this be avoided?
The general advice is to ACCEPT as many PTFs as possible up to but NOT including UM99901.
If maintenance was somehow APPLYed over the top of UM99901 by BYPASSing, then that maintenance will have to be RESTOREd as well as the usermod. After that, APPLY the PTFs that are needed, ACCEPT the PTFs, and then re-apply UM99901. Do not ACCEPT UM99901.