I'm having the exact same problem. readLine() is cutting a line in the middle. The line also contains toString() versions of UUIDs, as what looks to be the case of OP.
The weirdest thing is that it manages to process tens of thousands of lines with the same kind of data, and around line 32k the problem happens.
This is the line in the file:
0608 84424c 54a76548-275d-4dbc-8 97af9846-5395-40fd-9 405e0e82d1e9b-b 33122 ae81bfb0-ccc6-4c7a-ae0c-a016ef 8000f CR5a88f5b0081f504db00a1c500074fc21638AGRIFRPP835 GL8964710001000206 91e5df50-ad93-43af-b0ad-5df1ff4a394d 10082 PA5b74e83c-bb3c-411f-a927-c8da4f88932d33122 fcacd8a3-ed35-41de-8978-c18243
This is how the line is read by BufferedReader:
0608 84424c 54a76548-275d-4dbc-8 97af9846-5395-40fd-9 405e0e82d1e9b-b 33122 ae81bfb0-ccc6-4c7a-ae0c-a016ef 8000f CR5a88f5b0081f504db00a1c500074fc21638AGRIFRPP835 GL8964710001000206 91e5df50-ad93-43af-b0ad-5df
@Norm, the cut happens in between the characters f1. Their hexa representation seems to be 6631 according to this site.
Anybody has any idea of what's going on?