I have external lists connected to a sql server database. Since the last day, some of the lists do not display data; the lists are empty, only headers are shown. (Some lists still display data, though.) But the database tables contain data. I have changed nothing about connection properties or permissions. Has anyone encountered this problem before?
I had the same issue.
My first try was to create an additional Read List operation without the Wildcard filter.
I set that as default Read List operation, and created a list based on this. That worked, but my picker in for instance External Columns no longer had my wildcard filter.
I then sat my first Read List operation (with the wildcard filter) back to beeing default Read List op. Now they both worked ok.
In the end I found out I could just use default value of % on my wildcard filter. (This is for SQL Server)
The problem was that I had a wildcard filter in the readlist operation of the external content type. Although it had "ignore filter" checked with null value and default value was "none". I am not sure why this does not work.