I had a 114mb update on acr when i opened it today, upon finishing I kept recieving an odd "directory not found" error when i tried to open. I couldn't succesfully install to my C drive either when i went to reinstall it, but it did go to my D drive and the client was now working again. Yes I have save hand histories setting on, confirmed the hand histories are being saved here from the client, and confirmed this folder is in the "auto import folders" list in HM3.
For clarity D:\AmericasCardroom/handHistory is listed and checked off in HM3, and this is the folder ACR is set to save in and i have confirmed that. At the same time this occured HM3 updated, possible a beta update. I'm not sure what else to do but guess I am going to try to figure out why the C drive install was not succesful for ACR? The drive is not full just the installer gave an obscure error.
Edit: I have also confirmed I have the correct player name selected in HM3