Multisite Plugin Manager 3.1.2 has worked great on five of our WP multisite networks side by side with Ultimate TinyMCE Pro until UTMCE versions went above 7.3.
A white screen of death appears when upgrading to any version of UTMCE above 7.3 when Multisite Plugin Manager 3.1.2 is active.
Deactivating Multisite Plugin Manager eliminates the conflict and all versions of UTMCE above 7.3 run happily without issue.
Deactivating any verison of UTMCE above 7.3 allows Multisite Plugin Manager v 3.1.2 to work fine.
Running Multiste Plugin Manager v3.1.2 and UTMCE together works fine up to v7.3 but not above 7.3.
I have also reported this conflict to the developer of UltimateTiny MCE in the hopes that between both developers a solution can be devised so that both of these great plugins can once again play nice together.