Hi Michelle,
If you are using a flowgraph from version 3.8 while running GRC with version 3.9, you may be having the problem described here: https://wiki.gnuradio.org/index.php?title=Porting_Existing_Flowgraphs_to_a_Newer_Version#From_3.8_to_3.9 --- Barry Duggan KV4FV https://github.com/duggabe On Mon, 24 Jan 2022 19:55:51 -0500, Michelle wrote: hello, I'm using a FIR filter and I have the error : "Param - Taps(taps): Expression None is invalid for type'complex_vector'." my taps is : firdes.low_pass ( 1, samp_rate, frec_carrier, 25000,firdes.WIN_HAMMING ) samp_rate and frec_carrier are both variables in my graph. I don't understand why I have an error. Please could you tell me what I am doing wrong? Thank you.
