diff --git a/examples/spartan6/project.cfg b/examples/spartan6/project.cfg
index 079aba8..390b779 100644
--- a/examples/spartan6/project.cfg
+++ b/examples/spartan6/project.cfg
@@ -63,8 +63,8 @@ toplevel            = tb_toplevel
 vcdlevels           = 20
 runtime             = all
 fuse_opts           = --maxdelay work.glbl
-isim_opts           = -sdfmax /tb_toplevel/c_toplevel=%%D%%/OUT/synth/synth.sdf
-# %%D%% is replaced with the top directory of the project
+isim_opts           = -sdfmax /tb_toplevel/c_toplevel=~D~/OUT/synth/synth.sdf
+# ~D~ is replaced with the top directory of the project
 
 # Fileset
 files_vhdl          = SIM/tb_toplevel.vhd
diff --git a/remotesyn/toolchains/isim.py b/remotesyn/toolchains/isim.py
index b9b5420..1509138 100644
--- a/remotesyn/toolchains/isim.py
+++ b/remotesyn/toolchains/isim.py
@@ -19,8 +19,8 @@ def do(config, target, log, subprocesses, prefix='.'):
     build_dir = f'{prefix}/{build_dir}'
     out_dir = f'{prefix}/{out_dir}/{target}'
 
-    fuse_opts = fuse_opts.replace("%D%", prefix)
-    isim_opts = isim_opts.replace("%D%", prefix)
+    fuse_opts = fuse_opts.replace("~D~", prefix)
+    isim_opts = isim_opts.replace("~D~", prefix)
 
     log(" - creating output directories")
     os.makedirs(build_dir, exist_ok=True)
diff --git a/scripts/rmbuild b/scripts/rmbuild
index 5ed9b50..d556b1e 100644
--- a/scripts/rmbuild
+++ b/scripts/rmbuild
@@ -141,14 +141,13 @@ if __name__=="__main__":
         print("ERROR: Could not connect to server")
         exit(1)
 
-    # Send project identification
-    cmd(b'id' + struct.pack('>q', hash(host_key.get_base64())), channel)
-    # Send config
-    cmd(b'cf' + sstr(json.dumps({s:dict(config.items(s)) for s in config.sections()})), channel)
-
     subprocesses = []
 
     try:
+        # Send project identification
+        cmd(b'id' + struct.pack('>q', hash(host_key.get_base64())), channel)
+        # Send config
+        cmd(b'cf' + sstr(json.dumps({s:dict(config.items(s)) for s in config.sections()})), channel)
 
         toolchain = config.get(f'target.{target}', 'toolchain', fallback='NONE')
         if toolchain=='NONE':
@@ -177,7 +176,7 @@ if __name__=="__main__":
             exit(ret)
 
     except paramiko.ssh_exception.SSHException as e:
-        print("ERROR: Connection error...")
+        print("ERROR: Connection error...", e)
         for p in subprocesses:
             p.kill()
         exit(0)
diff --git a/scripts/rmserver b/scripts/rmserver
index 1d9ecc3..4e89f31 100644
--- a/scripts/rmserver
+++ b/scripts/rmserver
@@ -183,10 +183,10 @@ class SSHServer(paramiko.ServerInterface):
 
             return True
 
-        except Exception:
+        except Exception as e:
             global running
             if running:
-                print("ERROR: Unknown error")
+                print("ERROR: Unknown error:", e)
             return False
 
 class Connection(threading.Thread):