[stumped]

my library has frustratingly dropped overdrive and switched to RB digital
so I tried to ressurect and re configure my plug in( which i have not used for ages)
after making sure it was updated I tried to wing my way into tweaking it but I hit this error ( see below). tried to remove the plug in and start over but seems i cant do that either the error comes when I click on the plug in , in the plug in list, to tweak it, I get an empty window for select metadata fields? then this
calibre, version 4.3.0
ERROR: Unhandled exception: <b>WindowsError</b>:[Error 123] The filename, directory name, or volume label syntax is incorrect.: u'C:\\Users\\david\\AppData\\Roaming\\calibre\\met adata_sources\\Overdrive Link*.json'

calibre 4.3 embedded-python: True is64bit: False
Windows-10-10.0.18362-SP0 Windows ('32bit', 'WindowsPE')
32bit process running on 64bit windows
('Windows', '10', '10.0.18362')
Python 2.7.16+
Windows: ('10', '10.0.18362', 'SP0', u'Multiprocessor Free')
Interface language: en_GB
Successfully initialized third party plugins: DeDRM (6, 6, 0) && K4PC, K4Mac, Kindle Mobi and Topaz DeDRM (0, 4, 2) && Inept PDF DeDRM (0, 1, 9) && Inept Epub DeDRM (0, 2, 0) && EpubSplit (2, 8, 0) && Quality Check (1, 9, 11) && View Manager (1, 4, 3) && Open EPUB In Editor (1, 0, 0) && Copy Cover To Device (2, 0, 0) && Resize Cover (1, 0, 2) && KoboTouchExtended (3, 1, 5) && Modify ePub (1, 4, 0) && Count Pages (1, 9, 0) && Overdrive Link (2, 37, 0) && Open With (1, 5, 10) && KePub Output (3, 1, 3)
Traceback (most recent call last):
File "site-packages\calibre\gui2\preferences\plugins.py", line 292, in double_clicked
File "site-packages\calibre\gui2\preferences\plugins.py", line 373, in modify_plugin
File "site-packages\calibre\customize\__init__.py", line 177, in do_user_config
File "site-packages\calibre\ebooks\metadata\sources\base.py", line 270, in save_settings
File "site-packages\calibre\gui2\metadata\config.py", line 124, in commit
File "site-packages\calibre\gui2\metadata\config.py", line 52, in commit
File "site-packages\calibre\utils\config.py", line 448, in __setitem__
File "site-packages\calibre\utils\config.py", line 410, in commit
File "site-packages\calibre\utils\lock.py", line 111, in __enter__
File "site-packages\calibre\utils\lock.py", line 91, in lock_file
File "site-packages\calibre\utils\lock.py", line 81, in retry_for_a_time
File "site-packages\calibre\utils\lock.py", line 66, in windows_open
WindowsError: [Error 123] The filename, directory name, or volume label syntax is incorrect.: u'C:\\Users\\xxxxxx\\AppData\\Roaming\\calibre\\me tadata_sources\\Overdrive Link*.json'

Nb there is no blank character in metadata_sources ( though I see one when I save the post)