Is there any way to modify dividend (or split) information contained in a YahooFundamentalProvider file?

Assume I know a dividend amount shown by Yahoo! is incorrect. Reloading the file won't help, because I'll just get the same bad information again because it is wrong on Yahoo!'s server.

I can read the dividend information in a Strategy via Dividend (Yahoo! Finance). Is there any way to modify and save the corrected information as a .WLF file? I'm thinking of something similar to Bars.SaveToFile.

We're aware of cases in which Yahoo! has already applied a split to the raw data and therefore our client doesn't not need to adjust the data again. For these special cases, you can use the "Ignore Selected Splits" feature.

If many dividends are incorrect, perhaps we could look into a solution for editing those too. Do you have some examples?

This has now become a major issue for me. Yahoo! appears to have no 2014 year end dividend information for T. Rowe Price funds. For example, on 12/16/14, PRGTX went ex-dividend a $2.02 short-term capital gain distribution and a $1.27 long-term capital gain distribution. Neither of these show up, making the $3.35 drop in the price the following day look a lot bigger than the $0.06 drop taking the dividend into account.

I like the ability of Wealth-Lab Pro to perform Dividend Adjustment on Yahoo! data for mutual funds (and other securities that pay large or extraordinary dividends), which is one of the reasons I'm primarily relying on Yahoo! data these days. The failure to take these dividends into account generated a bunch of false sell signals, which I didn't realize until after I had acted on them.

Have you already contacted Yahoo! Finance support and suggested to fix their data?

Yes. Let me know if there is a better way to do that than https://yahoo.uservoice.com/forums/207809-finance-gs/suggestions/6902349-t-rowe-price-year-end-dividends-missing