I am BRAND NEW to LaTex and TexMaker. However, it was working before. I made a document before and used R with it and everything. Then I updated my Mac and it keeps saying "Log file not found" even though I'm opening the previously mentioned document just for practice. I read online to try uninstalling and installing, but the same problem is occurring.
If anyone can explain what to do in very basic basic speak, that would be great.
Answer
I had the same problem, after upgrading to OS X El Capitan. I have MacTEX-2016 distribution, but this also applies to later versions.
At document "What is installed.pdf" of MacTEX-2016 distribution, in page 3 you can read:
Our package also installs a crucial symbolic link:
/Library/TeX/texbin
This link points through the TeX Dist Data structure to the executables directory of the active distribution. Consequently, all GUI apps should be configured to find TeX at this location. This automatically happens for GUI applications provided by MacTeX. Users should not attempt to rewrite this link themselves when changing distributions; instead use the “Reconfigure Distributions...” command in TeX Live Utility described earlier.
Before 2015, MacTeX created a different symbolic link for the purpose, /usr/texbin. This changed in 2015 because El Capitan does not allow users to write into the /usr folder, although users can still write to /usr/local. The links /Library/TeX/texbin and /usr/texbin point to exactly the same spot and are entirely equivalent. Some third party GUI apps may still use /usr/texbin; reconfigure them to use /Library/TeX/texbin on El Capitan and higher.
For compatibility reasons, MacTeX installs both of these links on systems older than El Capitan. Only /Library/TeX/texbin is written on El Capitan and higher.
Thus, the path /Library/TeX/texbin is the location of all executables, and Texmaker should be configured properly at Preferences -> Commands using this path.