Acrobat DC - Blank PDFs, Multiple Processes Remain Open (Win 7)

I recently updated Acrobat DC (18.009.20044) on Windows 7.

When I open a PDF, either created by Acrobat DC or from another source, the PDF appears blank until I click the PDF screen.

Once I close the PDF the acrobat process remains open in the background and I cannot open another instance of Acrobat DC unless I go into Windows Task Manager and manually shut down the active acrobat.exe process.  If I don't manually stop the process, each time I try to open a PDF it will create another acrobat process so there will be multiple acrobat.exe processes showing in Windows Task Manager, but the program will not open until I manually stop them all and then try to open the PDF.

Please fix this, the previous version did not have any of these bugs.