[SOLVED] Delphi RIO PAServer in Linux raises IOError 11

I have a strange problem I cannot solve on my own:

Using Delphi 10.3 Rio Enterprise, on Linux (I tried fresh installs of Ubuntu 16.04 and Ubuntu 18.04 Desktop and Ubuntu 18.04 Server with GUI in VMWare Player 15) PAServer crashes with I/O Error 11 every time I start debugging. I can pull the SDK and Delphi deploys all files correctly. But trying to run ends with the crash and Delphi complaining that GDB Server is no longer available. I can run the program on the Linux host by starting it manually (of course without debugging).

It does not depend on the user in Linux, it also happens as root. Also, a non graphic appliation crashes even on non GUI Ubuntu server, always with IO Error 11.

Debugging with PAServer works well on OSX, Android and Windows. I of course tried a dead simple one form project without content with the same results.

I traced the Delphi PAClient with ProcMon, no evidence on that side. Then I tracked the Linux process with strace, which gave me this output:

write(1, "Starting Platform Assistant Serv"..., 49Starting Platform Assistant Server on port 64211
) = 49
write(1, "\n", 1
)                       = 1
write(1, "Type ? for available commands\n", 30Type ? for available commands
) = 30
socket(PF_INET6, SOCK_STREAM, IPPROTO_IP) = 5
close(5)                                = 0
socket(PF_INET, SOCK_STREAM, IPPROTO_IP) = 5
getsockopt(5, SOL_SOCKET, SO_TYPE, [1], [4]) = 0
getsockopt(5, SOL_TCP, TCP_NODELAY, [0], [4]) = 0
setsockopt(5, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
setsockopt(5, SOL_SOCKET, SO_REUSEPORT, [1], 4) = 0
bind(5, {sa_family=AF_INET, sin_port=htons(64211), sin_addr=inet_addr("0.0.0.0")}, 16) = 0
getsockname(5, {sa_family=AF_INET, sin_port=htons(64211), sin_addr=inet_addr("0.0.0.0")}, [16]) = 0
setsockopt(5, SOL_TCP, TCP_NODELAY, [1], 4) = 0
socket(PF_INET6, SOCK_STREAM, IPPROTO_IP) = 6
getsockopt(6, SOL_SOCKET, SO_TYPE, [1], [4]) = 0
getsockopt(6, SOL_TCP, TCP_NODELAY, [0], [4]) = 0
setsockopt(6, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
setsockopt(6, SOL_SOCKET, SO_REUSEPORT, [1], 4) = 0
bind(6, {sa_family=AF_INET6, sin6_port=htons(64211), inet_pton(AF_INET6, "::", &sin6_addr), sin6_flowinfo=0, sin6_scope_id=0}, 28) = 0
getsockname(6, {sa_family=AF_INET6, sin6_port=htons(64211), inet_pton(AF_INET6, "::", &sin6_addr), sin6_flowinfo=0, sin6_scope_id=0}, [28]) = 0
setsockopt(6, SOL_TCP, TCP_NODELAY, [1], 4) = 0
listen(5, 15)                           = 0
mmap(NULL, 8392704, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE|MAP_ANONYMOUS|MAP_STACK, -1, 0) = 0x7f8ab39f9000
mprotect(0x7f8ab39f9000, 4096, PROT_NONE) = 0
clone(child_stack=0x7f8ab41f8ff0, flags=CLONE_VM|CLONE_FS|CLONE_FILES|CLONE_SIGHAND|CLONE_THREAD|CLONE_SYSVSEM|CLONE_SETTLS|CLONE_PARENT_SETTID|CLONE_CHILD_CLEARTID, parent_tidptr=0x7f8ab41f99d0, tls=0x7f8ab41f9700, child_tidptr=0x7f8ab41f99d0) = 28987
sched_getparam(28987, [0])              = 0
sched_getscheduler(28987)               = 0 (SCHED_OTHER)
listen(6, 15)                           = 0
mmap(NULL, 8392704, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE|MAP_ANONYMOUS|MAP_STACK, -1, 0) = 0x7f8ab31f8000
mprotect(0x7f8ab31f8000, 4096, PROT_NONE) = 0
clone(child_stack=0x7f8ab39f7ff0, flags=CLONE_VM|CLONE_FS|CLONE_FILES|CLONE_SIGHAND|CLONE_THREAD|CLONE_SYSVSEM|CLONE_SETTLS|CLONE_PARENT_SETTID|CLONE_CHILD_CLEARTID, parent_tidptr=0x7f8ab39f89d0, tls=0x7f8ab39f8700, child_tidptr=0x7f8ab39f89d0) = 28988
sched_getparam(28988, [0])              = 0
sched_getscheduler(28988)               = 0 (SCHED_OTHER)
brk(0x1f55000)                          = 0x1f55000
brk(0x1f76000)                          = 0x1f76000
brk(0x1f97000)                          = 0x1f97000
brk(0x1fba000)                          = 0x1fba000
brk(0x1fdb000)                          = 0x1fdb000
mmap(NULL, 200704, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f8ab82b8000
mmap(NULL, 200704, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f8ab8287000
write(1, ">", 1>)                        = 1
read(0, 0xe0bf90, 128)                  = -1 EAGAIN (Resource temporarily unavailable)
read(0, 0xe0bf90, 128)                  = -1 EAGAIN (Resource temporarily unavailable)
shutdown(5, SHUT_WR)                    = 0
close(5)                                = 0
select(4, [3], NULL, NULL, {1, 0})      = 1 (in [3], left {0, 999997})
ioctl(3, FIONREAD, [1])                 = 0
read(3, "\0", 1)                        = 1
select(4, [3], NULL, NULL, {1, 0})      = 1 (in [3], left {0, 817727})
ioctl(3, FIONREAD, [1])                 = 0
read(3, "\0", 1)                        = 1
select(4, [3], NULL, NULL, {1, 0})      = 1 (in [3], left {0, 999997})
ioctl(3, FIONREAD, [1])                 = 0
read(3, "\0", 1)                        = 1
shutdown(6, SHUT_WR)                    = 0
close(6)                                = 0
select(4, [3], NULL, NULL, {1, 0})      = 1 (in [3], left {0, 974854})
ioctl(3, FIONREAD, [1])                 = 0
read(3, "\0", 1)                        = 1
shutdown(7, SHUT_WR)                    = 0
close(7)                                = 0
shutdown(8, SHUT_WR)                    = 0
close(8)                                = 0
select(0, NULL, NULL, NULL, {0, 500000}) = 0 (Timeout)
write(1, "EInOutError: I/O error 11\n", 26EInOutError: I/O error 11
) = 26

Thanks in advance for help!