What does the Simulation Results window show?

There are two problems with your simulation which are easily fixed.

:)

I am not sure where you got the 2N3904 symbols from but they are not from the EELib and do not seem be from the Spice Symbol library. Their spice pin numbering is wrong so they do not give the expected results in simulation.

The "interactive" LED symbols in the EELib are for "educational" purposes only and as such are suitable for use only in very low frequency simulations where they can be seen to flash at a rate considerably slower than the server to display update rate.

Your simulation oscillates at about 0.3Hz which is too fast for the display update rate to show a non-aliased display of alternating LED flashes.

Using these "interactive" LEDs also inhibits any WaveForm plot display creation.

To make your simulation (a) run and (b) show results that make any sense, please replace the LEDs with these:

and the 2N3904 transistors with these:

For more help with simulation in EasyEDA, especially since the change to LTspice, please read (3) in (2) in:

https://easyeda.com/forum/topic/How-to-ask-for-help-and-get-an-answer-71b17a40d15442349eaecbfae083e46a

Wow! My simulation result show no error so I didn't expect that:

Circuit: ** Sheet_1 **

Direct Newton iteration for .op point succeeded.

Date: Mon Jan 20 02:13:07 2020
Total elapsed time: 1.219 seconds.

tnom = 27
temp = 27
method = modified trap
totiter = 199973
traniter = 199963
tranpoints = 61231
accept = 42901
rejected = 18330
matrix size = 16
fillins = 12
solver = Normal
Matrix Compiler1: 1.71 KB object code size  1.4/1.2/[1.1]
Matrix Compiler2: 1.56 KB object code size  1.2/1.2/[1.2]

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Thank you for your help. I noted all your tips and it should help me to get again the WaveForm.