We had this problem yesterday. We found this question in Qaru and tried to move the data folder from the website folder to a separate folder. This immediately fixed the problem. Then you need to change this parameter in the Sitecore.config file (or Web.config):
<sc.variable name="dataFolder" value="/Data"/>
to point to a new folder. We asked Sitecore if this was a known issue and they did not have many ideas. Their only suggestion was that this could be caused by Sitecore caching.
Timhacker
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