i just upgraded to Ac 25 and when it try to open a file i get an error msg AC could not be launched because the following add ons are missing.
MEP modeller. i found this in the add ons downloads but its for AC 23.
Basic rendering engine.
why are these missing and where do i find them?
They are part of the installation. None of them are independently downloadable.
Either something is wrong with the installation file that you downloaded, or perhaps there were either permissions problems or an antivirus running (which blocked installation of those components). Given that you're on MacOS, neither of those seems likely (unless you elected to install somewhere other than your system Applications folder). Lots of us are on Macs and nobody has reported this issue here...
What country specific version are you trying to install? Did you try re-installing?
PS. Your signature says MacOS 11.4 ... if you haven't already, update to 11.5.2, although I don't see that as making a different in the installation issue you're experiencing.
One of the forum moderators • AC 25 USA and earlier • MacOS 11.6.1, iMac Pro
i thought that. so i just downloaded a new copy and tried to install, and if i remember correctly, it should have asked if i wanted to repair the existing installation, but i get an error msg that says it can't install AC 25 into a folder that contains other data.