In my book this is a good thing... whatever the issue is they've found, it's nice to see a company come out, hold their hands out and look to rectify the issue immediately. Kudos to Native Instruments.
Here's what NI Maschine team wrote on the NI forums along with advice to switch back to Maschine software version 2.4.0:
"Dear MASCHINE Users,
"Due to a significant defect in the MASCHINE 2.4.5 version, we are going to remove this version from our website and ServiceCenter. The teams are working on a fix for the problem, and we will publish the fixed version as soon as it is ready.
"In the meantime, version 2.4.0 can again be downloaded from the Updates page on the Native Instruments website after logging in to your account. We recommend that you use 2.4.0 until the new version is released, as there is a possibility that projects saved with version 2.4.5 will not be readable once we fix the defect."
Stay tuned to NI forums and AskAudio to find out when this will be re-released with the fix.