That’s exactly how Pamac/AUR broke for me…
I installed the “manjaro-system” update … Pamac then showed the list of other updates … and upon attempting to install them it spat out the certificate error.
Remembering I saw something about “percussive intervention required” I issued the terminal commands to update (which went without any errors), rebooted and that’s when “half” the package manager broke.
Moving the offening cert file out of the way didn’t solve the problem, nor did any subsequent update that came down the pipe solve the problem nor did the “lonesome” re-install of “ca-certificate-utils” solve the problem (that Pamac wouldn’t show search results from AUR). With this update “yaourt” finally worked again … so I could actually work out that the certificate situation was still totally f’d up (and surely not by me), hence why I had Pamac re-install all four “ca-certificate-*” packages which then ultimately solved the issue (though not for everybody it seems as there’s one reply above from an 17.0 Xfce user where it is still broken).
While I’m usually able to solve problems myself this was a wee bit tricky to track down when both tools refuse to work due to “downstream” (meaning from the maintainer to the end user) breakage.
Also, since no one from the “management floor” actually chimed in to either confirm the issue or offer advise I don’t really get the vibe that “Manjaro would like to know” … they seem to rather have taken the Apple/Microsoft approach to things, which is “blissful ignorance” (and no, that is not “flamebait” but a well deserved maneuver critique after 36+ hours into reports about the issue).