Hello I'm using version 2.27 FOP2.
Here's a screenshot of the normal, which shows that the Russian characters are not displayed correctly
(had to write a script that corrects the table fop2buttons because there instead of Russian characters were written question marks).
http://xn--b1adcybsawkyin9ch8c.xn--p1ai/images/work.png

After adding the queues, the names of subscribers participating in the queue are replaced by question marks. If you add a breakpoint, it is noticeable that at first all the characters are displayed correctly, but after fop2 request to the server, the characters are replaced.
http://xn--b1adcybsawkyin9ch8c.xn--p1ai/images/notwork.png

In the process of debugging, I found that fop2 server sends the string to base64, which after decoding has question marks. It turns out that the server generates the wrong line at once.

How to fix this error (can just write, where are the data for the button-queue?)

Sorry for bad english, I use google-translate :oops: