If you encounter errors with AppManager, the first place to check is in the log file which captures all error messages.
The log file can be found on your SITE ROOT > logs. An example of a log file would be 
.
If you see the following errors, then your web.config must be updated correctly.
WHEN PASSWORD IS WRONG
2016-02-11T02:15:11.4687394Z 0dc74b6c-eebf-53c0-1b33-63957412c647 101 1 Info Error 0
WHEN .CER USED INSTEAD OF .PFX
2016-02-11T02:16:25.0927184Z 0dc74b6c-eebf-53c0-1b33-63957412c647 101 1 Info Error 0
WHEN ISSUERID IS WRONG
2016-02-11T02:17:37.5809047Z 0dc74b6c-eebf-53c0-1b33-63957412c647 101 1 Info Error 0