You should note the fact that when you are using data plugin then the plugin controls the quotation database (see Understanding database concepts article), therefore you should NOT import quotes from ASCII files (this includes AmiQuote) for symbols that are already present in the real-time database.
If you do, the plugin will eventually overwrite your imports with the real-time data or your database will become corrupted (if you import end-of-day data over intraday database).
So please do not import ASCII (especially EOD data) into real-time intraday database fed by the plugin.
You may ask: why this is not disabled at all. The answer is that sometimes it is useful and sometimes it will work (but these are rare cases). For example it will work if you import INTRADAY data into the intraday database fed by QuoteTracker plugin and both the database and imported data have exactly the same bar interval.
It also works if you import the data for symbols that are NOT present in the database. In this case newly imported symbols are marked by ASCII importer as "use only local database for this symbol" (See Information window for details), so they are EXCLUDED from the real-time update. This is useful if you want to import some other data (even not quote data) and access it via Foreign function while using your real-time database.
So ASCII import is not disabled in real-time database but you have to use it with extreme care and know what you are doing.
Second thing is using Quote Editor. Although data are controlled by the plugin it is in most cases possible to use Quote Editor. However please note that you will be able to edit only 1-minute data or higher interval, and you will be able only to edit symbols that are backfilled completely (there is no running backfill for the particular symbol) and you will NOT be able to edit last three bars. This is so because last three bars are cached in the plugin. So you will be able to edit them only when new bars arrive making them 'older' than last three.