Issues after patching

Hello:

After patching in R12.1.3 I am having an issues log into applications. After I put in the credentials into the login page and it's taking long time and not responding and throwing the following generic error. Also I noticed that the login page buttons are greyed out.

 

The following patches were installed and I covered all pre-reqs and also replaced CUSTOM.pll with the original (out of box) CUSTOM.pll. - Basically we replaced the CUSTOM.pll with customization to out of box .pll. The reason for doing this after patching the AR & INV forms and .pll files were not generated successfully, so by replacing with the out of box CUSTOM.pll it resolves the issues.  Also there is no patching errors, please let me know the troubleshooting steps.  I patched two environments QA & PATCH and both are having the same issues.