It happens on <Enter> press (looks like plugin tries to analyse NL chars used across the file) and on copy/paste.

Automatic insertion of "import" statements (thru clicking on error marker) also gives such effect.

snapshot of unprintable chars

This is how it looks.
If I remove line 14, then next one (Assert._ import) is highlighted with error.

Then editor "goes crazy" with these different NL chars i.e. Enter may produce different symbols in different places in code.

I have the same problem.

fixing new lines outside eclipse helps, but after inserting imports with Ctrl+1 new lines got sometimes screwed up again. it can appear in another places, but somehow new imports triggers it more often.

Environment:
Windows 7 (64 bit), JDK 1.6 (build 21, 64 bit), Eclipse 3.6, Scala IDE from nightly-update-helios-2.8.1.RC2

other eclipse plugins: m2eclipse, subclipse, GWT (i think i've had this problem also without GWT)

tried several different configurations (32 bit, JDK 7, eclipse 3.5.2, stable build), set Workspace preferences to cp1251, Windows new line delimiter, same thing.

HELP!!!

The simple workaround for this is:
CTRL-A
CTRL-C
DELETE or BACKSPACE
CTRL-V

When you copy and paste your code, Eclipse seems to automagically fix all the newline characters, but only if you delete the original code.

Other workaround :
1. select file(s) in Package Explorer (should work also with Project Explorer)
2 File > Convert Line Delimiters To > ...[Default]

Updating tickets (#1000069, #1000195, #1000213, #1000223, #1000006, #1000021, #1000038, #1000048, #1000051, #1000052, #1000075, #1000103, #1000109, #1000115, #1000119, #1000156, #1000186, #1000207, #1000238, #1000262, #1000263, #380, #389, #683, #1238, #1331, #1635, #1645, #1715, #1729, #1744, #1783, #1839, #1869, #1885, #1890, #1902, #1918, #1919, #1924, #1925, #1946, #1964, #1991, #2131, #2233, #2342, #2348, #2408, #2459, #2499, #2523, #2572, #2582, #2602, #2614, #2615, #2675, #2710, #2745, #2763, #2816, #2830, #2834, #2878, #2879, #2887, #2888, #2901, #2911, #2912, #2922, #2937, #2938, #2942, #2951, #2955, #2957, #2961, #2964, #2965, #2974, #2975, #2989, #2990, #3002, #3055, #3070, #3087, #3135, #3139, #3173, #3182, #3184, #3200, #3213, #3214, #3221, #3243, #3251)

Updating tickets (#1000199, #1000200, #1000201, #1000204, #1000205, #1000209, #1000210, #1000211, #1000212, #1000215, #1000217, #1000218, #1000220, #1000222, #1000226, #1000227, #1000228, #1000230, #1000231, #1000232, #1000233, #1000235, #1000236, #1000237, #1000239, #1000240, #1000241, #1000242, #1000243, #1000244, #1000248, #1000249, #1000252, #1000253, #1000254, #1000255, #1000256, #1000258, #1000259, #1000032, #1000059, #1000062, #1000163, #1000197, #1000216, #1000221, #1000224, #1000121, #1000175, #1000219, #1000251, #1000069, #1000195, #1000213, #1000223, #1000006, #1000021, #1000038, #1000048, #1000051, #1000052, #1000075, #1000103, #1000109, #1000115, #1000119, #1000156, #1000186, #1000207, #1000238, #1000262, #1000263, #380, #389, #683, #1238, #1331, #1635, #1645, #1715, #1729, #1744, #1783, #1839, #1869, #1885, #1890, #1902, #1918, #1919, #1924, #1925, #1946, #1964, #1991, #2131, #2233, #2342, #2348, #2408)

Marking as invalid.

Eclipse is using the first instance of 'new line' as the default for any new 'new line', so it won't break an existing file.
Organize import/quick fix import generates the right 'new line' in 2.0.0 (maybe it was broken before).
No reproducible test case.