POTUS is the acronym for President of the United States. It is only used for the sitting President, so now refers to Pres. Trump. Probably used within the White House and Security Service for decades, it was explained and popularized on the show The West Wing. Note: This question initially asked why Pres.
miisclient.exe is a Windows 32 application that may lead to system malfunction if your computer is infected with miisclient.exe or missing the necessary components of miisclient.exe.iisclient.exe error can be fixed either by re-installing the associated program and then reboost your computer. You can also simply copy the same miisclient.exe file from another same operating system and replace the missing/broken file.
Had the same issue with several users. Resolved it by renaming the AdobeGCClient.exe in ProgramFiles(x86)\Common Files\Adobe\AdobeGCClient to .old instead. Not exactly a solution, but that file is just an Adobe Security file that checks to make sure users don't have illegal copies of Adobe products. 2015 Redistributable fix works as well though.