hi therePál Orosz, thanks for posting this on the Q&A
for azure custom translator, the key here is that every single line in both source and target files must match 1:1. even if u think they're identical, hidden characters or encoding issues can mess things up. open both files in a plain text editor like notepad++ (not word, never word %) and check line by line.
try that one ... save the files as UTF-8 BOM. sometimes that sneaky encoding difference trips up the validator. also, remove any trailing empty lines, yes, even one extra space can cause this error ))
now, for general advice that works anywhere... this isn't just a microsoft thing. any tool that does phrase alignment hates mismatched lines. try using a diff checker online to compare the files side by side. tools like WinMerge (free!) can highlight invisible differences u might miss.
aha, and here's a golden nugget, sometimes the issue isn't the content but the line endings. windows (CRLF) vs. linux (LF) can confuse the system. convert both files to the same format using something like VS Code's 'change end of line sequence' option.
good luck, and let me know if it works! 8-)
Alex