Issue:
You see the following in MM UI:
TimeoutError at /2k3JobWizard/QueuePool limit of size 200 overflow 10 reached, connection timed out, timeout 30Request Method: GET
How to fix:
The same service (Quest.MM4SP.WebAccess service) is responsible for User Interface and web part pair generation so, when there are a lot of errors for web part migration they affect web UI.
So, you need to fix issue with web part first.
When you open WebAccess.log file there are a lot of errors like:
** INFO ** GetNextPair with (u'EAE82F6E-EB28-45AC-9F6A-B02423A4BACC',)
** ERROR ** Error during next pair getting. 'utf8' codec can't decode byte 0x92 in position 26: unexpected code byte
** INFO ** _AddError with (u'EAE82F6E-EB28-45AC-9F6A-B02423A4BACC', u'\n <h1>UnicodeDecodeError at /wpmigration/GetNextPair</h1>\n <pre class="exception_value">', u'', u'2009-12-14 16:17:45', u'', u'', u'1', u'3', u'1')
To fix the error you need to delete all web part tables from MM4SP database:
When the WebAccess service starts it creates new tables.