Those issues are directly related to each other.
The right-sidebar in the admin "draws" on the page after all the payment modules have been processed. If there is an error while processing the initialization of one payment module, then the right sidebar is often not displayed, and in fact the list of payment modules halts just before showing the module in which the error occurred.
Such problems are almost always a result of uploading wrong files to wrong folders, or poorly-written addon modules.
Troubleshooting involves a few steps:
a) please list all addons you've added to your site
b) please list all the payment modules that *do* show in your Admin->Modules->Payment screen
c) please list all the files in your /includes/modules/payment folder
d) please list all the files in your /includes/languages/english/modules/payment folder
e) do you have any additional languages added to your site?




