grin: thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: Chain(Error { inner:

Hello, On a Debian 9.6, downloaded grin v0.5.1, install ok, md5sum ok, just launching

grin --floonet

… and nothing happens. Not even a grin process running.

edit: the issue is still present with grin v0.5.2

grin-server.log

20190110 16:19:40.169 INFO grin_util::logger - log4rs is initialized, file level: Debug, stdout level: Warn, min. level: Debug
20190110 16:19:40.169 INFO grin - Using configuration file at /home/userz/.grin/floo/grin-server.toml
20190110 16:19:40.169 INFO grin - This is Grin version 0.5.1 (git v0.5.1), built for x86_64-unknown-linux-gnu by rustc 1.31.1 (b6c32da9b 2018-12-18).
20190110 16:19:40.169 DEBUG grin - Built with profile "release", features "".
20190110 16:19:40.169 WARN grin::cmd::server - Starting GRIN in UI mode...
20190110 16:19:40.169 INFO grin_servers::grin::server - Starting server, genesis block: edc758c1
20190110 16:19:40.202 DEBUG grin_chain::txhashset::txhashset - Error returned, discarding txhashset extension: Other Error: output vs rproof MMRs different sizes 
 Cause: Unknown 
 Backtrace: 
20190110 16:19:40.219 ERROR grin_util::logger - 
thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: Chain(Error { inner: 

Other Error: output vs rproof MMRs different sizes })': libcore/result.rs:1009stack backtrace:
   0:     0x55982a88665d - backtrace::backtrace::trace::hd74837959dc31a2c
   1:     0x55982a885872 - <backtrace::capture::Backtrace as core::default::Default>::default::hfbe03539066da14f
   2:     0x55982a8858e9 - backtrace::capture::Backtrace::new::hd9d47426559d8b68
   3:     0x55982a80f390 - grin_util::logger::send_panic_to_log::{{closure}}::h0919c24963251ad6
   4:     0x55982a9570e6 - std::panicking::rust_panic_with_hook::hde420d6fd4455550
                        at libstd/panicking.rs:480
   5:     0x55982a956c31 - std::panicking::continue_panic_fmt::h8f394f3c578bcc76
                        at libstd/panicking.rs:390
   6:     0x55982a956b15 - rust_begin_unwind
                        at libstd/panicking.rs:325
   7:     0x55982a9a0b8c - core::panicking::panic_fmt::hca5dc4e8b320bc56
                        at libcore/panicking.rs:77
   8:     0x55982a0dbf49 - core::result::unwrap_failed::h31e8096bf431f8db
   9:     0x55982a0947b0 - grin::cmd::server::start_server::hb8666c7b00b2e941
  10:     0x55982a0953c8 - grin::cmd::server::server_command::ha8bb4497bcf97bf1
  11:     0x55982a11fd26 - grin::real_main::hb39a0190d567a13c
  12:     0x55982a11e665 - grin::main::hab1e977be2785e7c
  13:     0x55982a0f00b2 - std::rt::lang_start::{{closure}}::h2873acc0c7532388
  14:     0x55982a956ab2 - std::rt::lang_start_internal::{{closure}}::hafa8ecdacd368ebb
                        at libstd/rt.rs:59
                         - std::panicking::try::do_call::h8c0dbb48abbdf4df
                        at libstd/panicking.rs:310
  15:     0x55982a969189 - __rust_maybe_catch_panic
                        at libpanic_unwind/lib.rs:102
  16:     0x55982a93830a - std::panicking::try::hbc21637ba5f64d73
                        at libstd/panicking.rs:289
                         - std::panic::catch_unwind::h954917b922b8d970
                        at libstd/panic.rs:392
                         - std::rt::lang_start_internal::h5b2de3cc38c3b406
                        at libstd/rt.rs:58
  17:     0x55982a120a74 - main
  18:     0x7fe95dd722e0 - __libc_start_main
  19:     0x55982a060f80 - <unknown>
  20:                0x0 - <unknown>

I would be happy to help with that. How could I diagnose more ? Thanks